Index: gc_lang/fr/webext/background.js
==================================================================
--- gc_lang/fr/webext/background.js
+++ gc_lang/fr/webext/background.js
@@ -1,49 +1,59 @@
 // Background 
 
 "use strict";
 
+function showError (e) {
+    console.error(e.fileName + "\n" + e.name + "\nline: " + e.lineNumber + "\n" + e.message);
+}
 
 /*
     Worker (separate thread to avoid freezing Firefox)
 */
 let xGCEWorker = new Worker("gce_worker.js");
 
 xGCEWorker.onmessage = function (e) {
     // https://developer.mozilla.org/en-US/docs/Web/API/MessageEvent
-    switch (e.data[0]) {
-        case "grammar_errors":
-            console.log("GRAMMAR ERRORS");
-            console.log(e.data[1].aGrammErr);
-            browser.runtime.sendMessage({sCommand: "grammar_errors", aGrammErr: e.data[1].aGrammErr});
-            break;
-        case "spelling_and_grammar_errors":
-            console.log("SPELLING AND GRAMMAR ERRORS");
-            console.log(e.data[1].aSpellErr);
-            console.log(e.data[1].aGrammErr);
-            break;
-        case "text_to_test_result":
-            browser.runtime.sendMessage({sCommand: "text_to_test_result", sResult: e.data[1]});
-            break;
-        case "fulltests_result":
-            console.log("TESTS RESULTS");
-            browser.runtime.sendMessage({sCommand: "fulltests_result", sResult: e.data[1]});
-            break;
-        case "options":
-            console.log("OPTIONS");
-            console.log(e.data[1]);
-            break;
-        case "tokens":
-            console.log("TOKENS");
-            console.log(e.data[1]);
-            break;
-        case "error":
-            console.log("ERROR");
-            console.log(e.data[1]);
-            break;
-        default:
-            console.log("Unknown command: " + e.data[0]);
+    try {
+        switch (e.data[0]) {
+            case "grammar_errors":
+                console.log("GRAMMAR ERRORS");
+                console.log(e.data[1].aGrammErr);
+                browser.runtime.sendMessage({sCommand: "grammar_errors", aGrammErr: e.data[1].aGrammErr});
+                break;
+            case "spelling_and_grammar_errors":
+                console.log("SPELLING AND GRAMMAR ERRORS");
+                console.log(e.data[1].aSpellErr);
+                console.log(e.data[1].aGrammErr);
+                break;
+            case "text_to_test_result":
+                browser.runtime.sendMessage({sCommand: "text_to_test_result", sResult: e.data[1]});
+                break;
+            case "fulltests_result":
+                console.log("TESTS RESULTS");
+                browser.runtime.sendMessage({sCommand: "fulltests_result", sResult: e.data[1]});
+                break;
+            case "options":
+                console.log("OPTIONS");
+                console.log(e.data[1]);
+                break;
+            case "tokens":
+                console.log("TOKENS");
+                console.log(e.data[1]);
+                browser.browserAction.setPopup({popup: "panel/main.html"});
+                browser.runtime.sendMessage({sCommand: "show_tokens", oResult: e.data[1]});
+                break;
+            case "error":
+                console.log("ERROR");
+                console.log(e.data[1]);
+                break;
+            default:
+                console.log("Unknown command: " + e.data[0]);
+        }
+    }
+    catch (e) {
+        showError(e);
     }
 };
 
 xGCEWorker.postMessage(["init", {sExtensionPath: browser.extension.getURL("."), sOptions: "", sContext: "Firefox"}]);
 
@@ -101,8 +111,11 @@
     // confusing: no way to get the node where we click?!
     switch (xInfo.menuItemId) {
         case "grammar_checking":
             break;
         case "lexicographer":
+            if (xInfo.selectionText) {
+                xGCEWorker.postMessage(["getListOfTokens", {sText: xInfo.selectionText}]);
+            }
             break;
     }
 });

Index: gc_lang/fr/webext/panel/main.js
==================================================================
--- gc_lang/fr/webext/panel/main.js
+++ gc_lang/fr/webext/panel/main.js
@@ -1,10 +1,12 @@
 // Main panel
 
 "use strict";
 
-
+/*
+    Common functions
+*/
 function showError (e) {
     console.error(e.fileName + "\n" + e.name + "\nline: " + e.lineNumber + "\n" + e.message);
 }
 
 function showPage (sPageName) {
@@ -28,10 +30,18 @@
     }
     catch (e) {
         showError(e);
     }
 }
+
+function startWaitIcon () {
+    document.getElementById("waiticon").hidden = false;
+}
+
+function stopWaitIcon () {
+    document.getElementById("waiticon").hidden = true;
+}
 
 
 /*
     Events
 */
@@ -81,18 +91,96 @@
 
 /*
     Messages received
 */
 function handleMessage (oMessage, xSender, sendResponse) {
-    //console.log(xSender);
+    console.log(xSender);
     switch(oMessage.sCommand) {
+        case "show_tokens":
+            console.log("show tokens");
+            addParagraphOfTokens(oMessage.oResult);
+            break;
         case "text_to_test_result":
-            document.getElementById("tests_result").textContent = oMessage.sResult;
+            showTestResult(oMessage.sResult);
             break;
         case "fulltests_result":
-            document.getElementById("tests_result").textContent = oMessage.sResult;
+            showTestResult(oMessage.sResult);
             break;
     }
     sendResponse({sCommand: "none", sResult: "done"});
 }
 
 browser.runtime.onMessage.addListener(handleMessage);
+
+
+/*
+
+    DEDICATED FUNCTIONS 
+
+*/
+
+
+/*
+    Test page
+*/
+function showTestResult (sText) {
+    document.getElementById("tests_result").textContent = sText;
+}
+
+
+/*
+    Lexicographer page
+*/
+
+function addSeparator (sText) {
+    if (document.getElementById("tokens_list").textContent !== "") {
+        let xElem = document.createElement("p");
+        xElem.className = "separator";
+        xElem.textContent = sText;
+        document.getElementById("tokens_list").appendChild(xElem);
+    }
+}
+
+function addMessage (sClass, sText) {
+    let xNode = document.createElement("p");
+    xNode.className = sClass;
+    xNode.textContent = sText;
+    document.getElementById("tokens_list").appendChild(xNode);
+}
+
+function addParagraphOfTokens (lElem) {
+    try {
+        let xNodeDiv = document.createElement("div");
+        xNodeDiv.className = "paragraph";
+        for (let oToken of lElem) {
+            xNodeDiv.appendChild(createTokenNode(oToken));
+        }
+        document.getElementById("tokens_list").appendChild(xNodeDiv);
+    }
+    catch (e) {
+        showError(e);
+    }
+}
+
+function createTokenNode (oToken) {
+    let xTokenNode = document.createElement("div");
+    xTokenNode.className = "token " + oToken.sType;
+    let xTokenValue = document.createElement("b");
+    xTokenValue.className = oToken.sType;
+    xTokenValue.textContent = oToken.sValue;
+    xTokenNode.appendChild(xTokenValue);
+    let xSep = document.createElement("s");
+    xSep.textContent = " : ";
+    xTokenNode.appendChild(xSep);
+    if (oToken.aLabel.length === 1) {
+        xTokenNode.appendChild(document.createTextNode(oToken.aLabel[0]));
+    } else {
+        let xTokenList = document.createElement("ul");
+        for (let sLabel of oToken.aLabel) {
+            let xTokenLine = document.createElement("li");
+            xTokenLine.textContent = sLabel;
+            xTokenList.appendChild(xTokenLine);
+        }
+        xTokenNode.appendChild(xTokenList);
+    }
+    return xTokenNode;
+}