diff --git a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/PairingHandler.kt b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/PairingHandler.kt
index fd2b1b4..f745c8e 100644
--- a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/PairingHandler.kt
+++ b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/PairingHandler.kt
@@ -16,6 +16,7 @@ object PairingHandler: PairgothApiHandler {
     override fun get(request: HttpServletRequest, response: HttpServletResponse): Json? {
         val tournament = getTournament(request)
         val round = getSubSelector(request)?.toIntOrNull() ?: badRequest("invalid round number")
+        if (round > tournament.lastRound() + 1) badRequest("invalid round: previous round has not been played")
         val playing = tournament.games(round).values.flatMap {
             listOf(it.black, it.white)
         }.toSet()
diff --git a/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/ApiTool.kt b/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/ApiTool.kt
index 41c4268..dabcb33 100644
--- a/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/ApiTool.kt
+++ b/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/ApiTool.kt
@@ -6,25 +6,37 @@ import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.internal.EMPTY_REQUEST
+import org.slf4j.LoggerFactory
 
 class ApiTool {
     companion object {
         const val JSON = "application/json"
         val apiRoot = System.getProperty("pairgoth.api.external.url")?.let { "${it.removeSuffix("/")}/" }
             ?: throw Error("no configured API url")
+        val logger = LoggerFactory.getLogger("api")
     }
     private val client = OkHttpClient()
     private fun prepare(url: String) = Request.Builder().url("$apiRoot$url").header("Accept", JSON)
     private fun Json.toRequestBody() = toString().toRequestBody(JSON.toMediaType())
     private fun Request.Builder.process(): Json {
-        client.newCall(build()).execute().use { response ->
-            if (response.isSuccessful) {
-                when (response.body?.contentType()?.subtype) {
-                    null -> throw Error("null body or content type")
-                    "json" -> return Json.parse(response.body!!.string()) ?: throw Error("could not parse json")
-                    else -> throw Error("unhandled content type: ${response.body!!.contentType()}")
+        try {
+            return client.newCall(build()).execute().use { response ->
+                if (response.isSuccessful) {
+                    when (response.body?.contentType()?.subtype) {
+                        null -> throw Error("null body or content type")
+                        "json" -> Json.parse(response.body!!.string()) ?: throw Error("could not parse json")
+                        else -> throw Error("unhandled content type: ${response.body!!.contentType()}")
+                    }
+                } else {
+                    when (response.body?.contentType()?.subtype) {
+                        "json" -> Json.parse(response.body!!.string()) ?: throw Error("could not parse error json")
+                        else -> throw Error("${response.code} ${response.message}")
+                    }
                 }
-            } else throw Error("api call failed: ${response.code} ${response.message}")
+            }
+        } catch (e: Throwable) {
+            logger.error("api call failed", e)
+            return Json.Object("error" to e.message)
         }
     }
 
diff --git a/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/PairgothTool.kt b/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/PairgothTool.kt
new file mode 100644
index 0000000..75a0abf
--- /dev/null
+++ b/view-webapp/src/main/kotlin/org/jeudego/pairgoth/view/PairgothTool.kt
@@ -0,0 +1,11 @@
+package org.jeudego.pairgoth.view
+
+import com.republicate.kson.Json
+
+/**
+ * Generic utilities
+ */
+
+class PairgothTool {
+    public fun toMap(array: Json.Array) = array.map { ser -> ser as Json.Object }.associateBy { it.getLong("id")!! }
+}
\ No newline at end of file
diff --git a/view-webapp/src/main/sass/tour.scss b/view-webapp/src/main/sass/tour.scss
index 684af4a..7e057e0 100644
--- a/view-webapp/src/main/sass/tour.scss
+++ b/view-webapp/src/main/sass/tour.scss
@@ -164,7 +164,7 @@
     max-width: 40vw;
     border: solid 2px darkgray;
     border-radius: 5px;
-    padding-top: 1em;
+    padding: 1em 0.5em;
     &:before {
       position: absolute;
       content: attr(title);
@@ -175,6 +175,21 @@
       font-size: smaller;
       font-weight: bold;
     }
+    .listitem {
+      display: flex;
+      flex-flow: row nowrap;
+      justify-content: space-between;
+      gap: 1em;
+      cursor: pointer;
+      user-select: none;
+      &:hover {
+        background-color: rgba(50, 50, 50, .2);
+      }
+      &.selected {
+        background-color: rgba(100,200,255,200);
+        cursor: grab;
+      }
+    }
   }
   #pairing-buttons {
     display: flex;
diff --git a/view-webapp/src/main/webapp/WEB-INF/tools.xml b/view-webapp/src/main/webapp/WEB-INF/tools.xml
index 811a5d3..6d68015 100644
--- a/view-webapp/src/main/webapp/WEB-INF/tools.xml
+++ b/view-webapp/src/main/webapp/WEB-INF/tools.xml
@@ -4,13 +4,14 @@
     <toolbox scope="application">
         <tool key="translate" class="org.jeudego.pairgoth.view.TranslationTool"/>
         <tool key="strings" class="org.apache.commons.lang3.StringUtils"/>
+        <tool key="utils" class="org.jeudego.pairgoth.view.PairgothTool"/>
         <!--
         <tool key="number" format="#0.00"/>
         <tool key="date" locale="fr_FR" format="yyyy-MM-dd"/>
         <tool key="inflector" class="org.atteo.evo.inflector.English"/>
         -->
     </toolbox>
-
+Exception
     <toolbox scope="session">
         <!--
         <tool key="oauth" class="org.jeudego.egc2024.tool.OAuthTool"/>
diff --git a/view-webapp/src/main/webapp/js/api.js b/view-webapp/src/main/webapp/js/api.js
index db6906e..eaac9b7 100644
--- a/view-webapp/src/main/webapp/js/api.js
+++ b/view-webapp/src/main/webapp/js/api.js
@@ -33,6 +33,12 @@ function success() {
   $('#error').addClass('hidden');
 }
 
+function showError(message) {
+  console.error(message);
+  $('#error')[0].innerText = message;
+  $('#error').removeClass('hidden');
+}
+
 function error(response) {
   const contentType = response.headers.get("content-type");
   let promise =
@@ -40,10 +46,8 @@ function error(response) {
     ? response.json().then(json => json.error || "unknown error")
     : Promise.resolve(response.statusText);
   promise.then(message => {
-    message = message.replaceAll(/([a-z])([A-Z])/g,"$1 $2").toLowerCase()
-    console.error(message);
-    $('#error')[0].innerText = message;
-    $('#error').removeClass('hidden');
+    message = message.replaceAll(/([a-z])([A-Z])/g,"$1 $2").toLowerCase();
+    showError(message);
   });
 }
 
diff --git a/view-webapp/src/main/webapp/js/domhelper.js b/view-webapp/src/main/webapp/js/domhelper.js
index 7f63ac8..7c392c0 100644
--- a/view-webapp/src/main/webapp/js/domhelper.js
+++ b/view-webapp/src/main/webapp/js/domhelper.js
@@ -66,17 +66,41 @@ Node.prototype.offset = function() {
 NodeList.prototype.offset = function() {
   this.item(0).offset();
 }
-Element.prototype.attr = function (key) {
-  return this.attributes[key].value;
+Element.prototype.attr = function (key, value) {
+  if (typeof(value) === 'undefined') {
+    return this.attributes[key].value;
+  } else {
+    this.setAttribute(key, value);
+    return this;
+  }
 }
-NodeList.prototype.attr = function(key) {
-  this.item(0).attr(key);
+NodeList.prototype.attr = function(key, value) {
+  if (typeof(value) === 'undefined') {
+    return this.item(0).attr(key);
+  } else {
+    this.forEach(elem => {
+      elem.attr(key, value);
+    });
+    return this;
+  }
 }
-Element.prototype.data = function (key) {
-  return this.attributes[`data-${key}`].value
+Element.prototype.data = function (key, value) {
+  if (typeof(value) === 'undefined') {
+    return this.attributes[`data-${key}`].value
+  } else {
+    this.setAttribute(`data-${key}`, value);
+    return this;
+  }
 }
-NodeList.prototype.data = function(key) {
-  this.item(0).data(key);
+NodeList.prototype.data = function(key, value) {
+  if (typeof(value) === 'undefined') {
+    this.item(0).data(key);
+  } else {
+    this.forEach(elem => {
+      elem.data(key, value);
+    })
+    return this;
+  }
 }
 NodeList.prototype.show = function() {
   this.item(0).show();
@@ -147,3 +171,25 @@ NodeList.prototype.focus = function() {
   let first = this.item(0);
   if (first) first.focus();
 }
+
+Element.prototype.index = function(selector) {
+  let i = 0;
+  let child = this;
+  while ((child = child.previousSibling) != null) {
+    if (typeof(selector) === 'undefined' || child.nodeType === Node.ELEMENT_NODE && child.matches(selector)) {
+      ++i;
+    }
+  }
+  return i;
+}
+
+NodeList.prototype.filter = function(selector) {
+  let result = [];
+  this.forEach(elem => {
+    if (elem.nodeType === Node.ELEMENT_NODE && elem.matches(selector)) {
+      result.push(elem);
+    }
+  });
+  return Reflect.construct(Array, result, NodeList);
+}
+
diff --git a/view-webapp/src/main/webapp/js/tour-pairing.inc.js b/view-webapp/src/main/webapp/js/tour-pairing.inc.js
index ae361c4..1abaf96 100644
--- a/view-webapp/src/main/webapp/js/tour-pairing.inc.js
+++ b/view-webapp/src/main/webapp/js/tour-pairing.inc.js
@@ -1,2 +1,23 @@
+let focused = undefined;
+
 onLoad(()=>{
+  $('.listitem').on('click', e => {
+    if (e.shiftKey && typeof(focused) !== 'undefined') {
+      let from = focused.index('.listitem');
+      let to = e.target.closest('.listitem').index('.listitem');
+      if (from > to) {
+        let tmp = from;
+        from = to;
+        to = tmp;
+      }
+      let parent = e.target.closest('.multi-select');
+      let children = parent.childNodes.filter('.listitem');
+      for (let j = from; j <= to; ++j) {
+        children.item(j).addClass('selected');
+        children.item(j).attr('draggable', true);
+      }
+    } else {
+      focused = e.target.closest('.listitem').toggleClass('selected').attr('draggable', true);
+    }
+  });
 });
diff --git a/view-webapp/src/main/webapp/tour-pairing.inc.html b/view-webapp/src/main/webapp/tour-pairing.inc.html
index 9d1ee5c..27b5002 100644
--- a/view-webapp/src/main/webapp/tour-pairing.inc.html
+++ b/view-webapp/src/main/webapp/tour-pairing.inc.html
@@ -1,14 +1,26 @@
-#set($paired = $api.get("tour/${params.id}/part"))
 <div class="tab-content" id="pairing">
   <div id="pairing-content">
     <div id="pairing-round">
       Pairings for round
       <button class="ui floating choose-round prev-round button">&laquo;</button>
-      <span class="active-round">1</span>
+      <span class="active-round">$round</span>
       <button class="ui floating choose-round next-round button">&raquo;</button>
     </div>
     <div id="pairing-lists">
       <div id="pairables" class="multi-select" title="pairable players">
+#set($pairables = $api.get("tour/${params.id}/pair/$round"))
+#if($pairables.isObject() && $pairables.error)
+        <script type="text/javascript">
+          onLoad(() => {
+            showError("$pairables.error")
+          });
+        </script>
+#else
+  #foreach($p in $pairables)
+    #set($part = $pmap[$p])
+        <div class="listitem pairable"><span>$part.name $part.firstname</span><span>$part.country #rank($part.rank)</span></div>
+  #end
+#end
       </div>
       <div id="pairing-buttons">
         <button id="pair" class="ui blue right labeled icon floating button">
diff --git a/view-webapp/src/main/webapp/tour-registration.inc.html b/view-webapp/src/main/webapp/tour-registration.inc.html
index 8164089..4d2aa49 100644
--- a/view-webapp/src/main/webapp/tour-registration.inc.html
+++ b/view-webapp/src/main/webapp/tour-registration.inc.html
@@ -2,6 +2,7 @@
   <div id="reg-view">
     <div id="players-list" class="roundbox">
 #set($parts = $api.get("tour/${params.id}/part"))
+#set($pmap = $utils.toMap($parts))
       <table id="players" class="ui celled selectable striped table">
         <thead>
           <th>name</th>
diff --git a/view-webapp/src/main/webapp/tour.html b/view-webapp/src/main/webapp/tour.html
index 29a10fc..2ee112d 100644
--- a/view-webapp/src/main/webapp/tour.html
+++ b/view-webapp/src/main/webapp/tour.html
@@ -20,6 +20,15 @@
 </div>
   #end
 #end
+## set up some global context templating variables
+#if($tour)
+  #set($round = $math.toInteger($!params.round))
+  #if(!$round)
+    #set($round = 1)
+  #else
+    #set($round = $math.min($math.max($round, 1), $tour.rounds))
+  #end
+#end
 <div class="section">
   <h1 class="centered title">#if($tour)$tour.name#{else}New Tournament#end</h1>
 #if($tour)
@@ -65,7 +74,8 @@
 #if($tour)
   const tour_id = ${tour.id};
   const tour_rounds = ${tour.rounds};
-  let activeRound = 1;
+  let activeRound = ${round};
+  // $params
 #end
 #set($datepickerLocale = $translate.datepickerLocale($request.lang, $request.loc))
   const datepickerLocale = '$datepickerLocale';
@@ -106,12 +116,6 @@
     }
     if (window.location.hash) {
       let step = window.location.hash.substring(1);
-      let suffix = /^(.)+-(\d+)$/.exec(step);
-      if (suffix) {
-        step = suffix[1];
-        activeRound = parseInt(suffix[2]);
-        $('.active-round').forEach(e => e.innerHTML = `${activeRound}`);
-      }
       chooseStep(step);
     }
 
@@ -148,14 +152,16 @@
       $('.next-round').addClass('disabled');
     }
     $('.prev-round').on('click', e => {
-      let base = window.location.href.replace(/-\d+$/g, '');
-      window.location.href = `#${base}-${activeRound - 1}`;
-      window.location.reload();
+      let round = activeRound - 1;
+      if (round > 0) {
+        window.location.search = `id=${tour_id}&round=${round}`
+      }
     });
     $('.next-round').on('click', e => {
-      let base = window.location.href.replace(/-\d+$/g, '');
-      window.location.href = `#${base}-${activeRound + 1}`;
-      window.location.reload();
+      let round = activeRound + 1;
+      if (round <= tour_rounds) {
+        window.location.search = `id=${tour_id}&round=${round}`
+      }
     });
   });
   // ]]#