--- loncom/interface/lonhtmlcommon.pm	2015/03/31 13:46:01	1.359
+++ loncom/interface/lonhtmlcommon.pm	2015/04/01 16:14:46	1.360
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common html routines
 #
-# $Id: lonhtmlcommon.pm,v 1.359 2015/03/31 13:46:01 damieng Exp $
+# $Id: lonhtmlcommon.pm,v 1.360 2015/04/01 16:14:46 damieng Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1308,6 +1308,7 @@ sub htmlareaselectactive {
     function startRichEditor(id) {
         // fix character entities inside <m>
         // NOTE: this is not fixing characters inside <parse>
+        // NOTE: < and > inside <chem> should fix automatically because there should not be a letter after <.
         var ta = document.getElementById(id);
         var value = ta.value;
         var in_m = false; // in the m element
@@ -1351,36 +1352,41 @@ sub htmlareaselectactive {
     
     function destroyRichEditor(id) {
     	CKEDITOR.instances[id].destroy();
-        // replace character entities &lt; and &gt; in <m>
+        // replace character entities &lt; and &gt; in <m> and <chem>
         // and "&amp;fctname(" by "&fctname("
         // and the quotes inside functions: "&fct(1, &quot;a&quot;)" -> "&fct(1, "a")"
         var ta = document.getElementById(id);
         var value = ta.value;
-        var in_m = false; // in the m element
-        var in_text = false; // in the text inside the m element
-        var im = -1; // position of <m>
+        var in_element = false; // in the m or chem element
+        var tagname = ""; // m or chem
+        var in_text = false; // in the text inside the element
+        var im = -1; // position of start tag
         var it = -1; // position of the text inside
         for (var i=0; i<value.length; i++) {
-            if (value.substr(i, 2) == "<m") {
-                // ignore previous <m> if found twice
-                in_m = true;
+            if (value.substr(i, 2) == "<m" || value.substr(i, 5) == "<chem") {
+                // ignore previous tags if found twice
+                in_element = true;
+                if (value.substr(i, 2) == "<m")
+                    tagname = "m";
+                else
+                    tagname = "chem";
                 in_text = false;
                 im = i;
                 it = -1;
-            } else if (in_m) {
+            } else if (in_element) {
                 if (!in_text) {
                     if (value.charAt(i) == ">") {
                         in_text = true;
                         it = i+1;
                     }
-                } else if (value.substr(i, 4) == "</m>") {
-                    in_m = false;
+                } else if (value.substr(i, 3+tagname.length) == "</"+tagname+">") {
+                    in_element = false;
                     var text = value.substr(it, i-it);
                     var l1 = text.length;
                     text = text.replace(/&lt;/g, "<");
                     text = text.replace(/&gt;/g, ">");
                     var l2 = text.length;
-                    value = value.substr(0, it) + text + "</m>" + value.substr(i+4);
+                    value = value.substr(0, it) + text + value.substr(i);
                     i = i + (l2-l1);
                 }
             }