Index: moodle/mod/lamslesson/mod_form.php
===================================================================
diff -u -rc38008e06c832aaf08e1bcb50577e26cbfc43420 -r5cb64dadd9549c48b1e0c2aa0896df2711a06d39
--- moodle/mod/lamslesson/mod_form.php	(.../mod_form.php)	(revision c38008e06c832aaf08e1bcb50577e26cbfc43420)
+++ moodle/mod/lamslesson/mod_form.php	(.../mod_form.php)	(revision 5cb64dadd9549c48b1e0c2aa0896df2711a06d39)
@@ -29,9 +29,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$PAGE->requires->yui2_lib('yahoo-dom-event');
-$PAGE->requires->yui2_lib('treeview');
-
 require_once($CFG->dirroot.'/course/moodleform_mod.php');
 
 class mod_lamslesson_mod_form extends moodleform_mod {
@@ -110,13 +107,13 @@
 
         $authorpreviewbutton .= html_writer::start_tag('div', array('id' => 'buttons', 'style' => 'float:right;'));
         // Preview button
-        $authorpreviewbutton .= html_writer::start_tag('span', array('id' => 'previewbutton', 'style' => 'visibility:hidden;', 'class' => 'yui-button yui-link-button'));
+        $authorpreviewbutton .= html_writer::start_tag('span', array('id' => 'previewbutton', 'style' => 'visibility:hidden;', 'class' => 'yui3-button yui3-link-button'));
         $authorpreviewbutton .= html_writer::start_tag('span', array('class' => 'first-child'));
         $authorpreviewbutton .= html_writer::link('#nogo', $openpreviewlabel, array('onclick' => js_writer::function_call('openPreview', array('1' => $previewurl, '2' => 'preview', '3' => 0))));
         $authorpreviewbutton .= html_writer::end_tag('span');
         $authorpreviewbutton .= html_writer::end_tag('span');
 	//Authoring button
-        $authorpreviewbutton .= html_writer::start_tag('span', array('id' => 'authorbutton', 'class' => 'yui-button yui-link-button'));
+        $authorpreviewbutton .= html_writer::start_tag('span', array('id' => 'authorbutton', 'class' => 'yui3-button yui3-link-button'));
         $authorpreviewbutton .= html_writer::start_tag('span', array('class' => 'first-child'));
         $authorpreviewbutton .= html_writer::link('#nogo', $openauthorlabel, array('onclick' => js_writer::function_call('openAuthor', array('1' => $authorurl, '2' => 'author', '3' => 0))));
         $authorpreviewbutton .= html_writer::end_tag('span');
@@ -128,9 +125,8 @@
     	$treecomponent = html_writer::tag('div', '' , array('id' => 'treeDiv'));
     	$treecomponent .= html_writer::tag('div', '' , array('id' => 'updatesequence'));
 
-    	$treecomponent .= html_writer::tag('script', 'var tree = new YAHOO.widget.TreeView("treeDiv",['. $lds .']);tree.getNodeByIndex(1).expand(true);tree.getNodeByIndex(2).expand(true);', array('type' => 'text/javascript'));
-    	$treecomponent .= html_writer::script('', $CFG->wwwroot.'/mod/lamslesson/tree.js');
-
+    	$treecomponent .= html_writer::tag('script', 'YUI().use("yui2-treeview","yui2-dom-event", function(Y) {var YAHOO = Y.YUI2; var tree = new YAHOO.widget.TreeView("treeDiv",['. $lds .']);tree.getNodeByIndex(1).expand(true);tree.getNodeByIndex(2).expand(true);tree.render();tree.subscribe("clickEvent",function(oArgs) {selectSequence(oArgs.node.data.id, oArgs.node.label);})});', array('type' => 'text/javascript'));
+	
     	// Now we put the two html chunks together
     	$html = $authorpreviewbutton . $treecomponent;
 
Index: moodle/mod/lamslesson/settings.php
===================================================================
diff -u -rcebd906a53797f8b28e2d1100620be09dffb9a44 -r5cb64dadd9549c48b1e0c2aa0896df2711a06d39
--- moodle/mod/lamslesson/settings.php	(.../settings.php)	(revision cebd906a53797f8b28e2d1100620be09dffb9a44)
+++ moodle/mod/lamslesson/settings.php	(.../settings.php)	(revision 5cb64dadd9549c48b1e0c2aa0896df2711a06d39)
@@ -51,7 +51,7 @@
     $html = html_writer::script('', $CFG->wwwroot.'/mod/lamslesson/validate.js');
     $html .=  html_writer::tag('p', get_string('validationinfo', 'lamslesson')); 
     $html .=  html_writer::start_tag('div', array('style' => 'text-align:center;padding-top: 15px; padding-bottom:5px;'));
-    $html .=  html_writer::start_tag('span', array('id' => 'validatebutton', 'class' => 'yui-button yui-link-button'));
+    $html .=  html_writer::start_tag('span', array('id' => 'validatebutton', 'class' => 'yui3-button yui3-link-button'));
     $html .=  html_writer::tag('a', get_string('validationbutton', 'lamslesson'), 
 		array('id' => 'validatebtn', 
 			'name' => 'validatebtn', 
Index: moodle/mod/lamslesson/view.php
===================================================================
diff -u -r80acd159361b65ce02deaae0f5d232f6c3d31f3f -r5cb64dadd9549c48b1e0c2aa0896df2711a06d39
--- moodle/mod/lamslesson/view.php	(.../view.php)	(revision 80acd159361b65ce02deaae0f5d232f6c3d31f3f)
+++ moodle/mod/lamslesson/view.php	(.../view.php)	(revision 5cb64dadd9549c48b1e0c2aa0896df2711a06d39)
@@ -97,15 +97,15 @@
 if ($canparticipate || $canmanage) {
   $learnerurl = lamslesson_get_url($USER->username, $locale['lang'], $locale['country'], $lamslesson->lesson_id, $course->id, $course->fullname, $course->timecreated, LAMSLESSON_PARAM_LEARNER_METHOD);
   echo '<div class="centerlink">';
-  echo '<span id="learnerbutton" class="yui-button yui-link-button"><span class="first-child"> ';
+  echo '<span id="learnerbutton" class="yui3-button yui3-link-button"><span class="first-child"> ';
   echo $OUTPUT->action_link($learnerurl, get_string('openlesson', 'lamslesson'), new popup_action('click', $learnerurl, '', array('height' => 600, 'width' => 996)));
   echo '</span></span>';
   echo '</div>';
 }
 if ($canmanage) {
     $monitorurl = lamslesson_get_url($USER->username, $locale['lang'], $locale['country'], $lamslesson->lesson_id, $course->id, $course->fullname, $course->timecreated, LAMSLESSON_PARAM_MONITOR_METHOD);
   echo '<div class="centerlink">';
-  echo '<span id="monitorbutton" class="yui-button yui-link-button"><span class="first-child"> ';
+  echo '<span id="monitorbutton" class="yui3-button yui3-link-button"><span class="first-child"> ';
   echo $OUTPUT->action_link($monitorurl, get_string('openmonitor', 'lamslesson'), new popup_action('click', $monitorurl, '', array('height' => 600, 'width' => 996)));
   echo '</span></span>';
   echo '</div>';