function initSubjectsTree(){
		//rendre les erreurs silencieuses en prod
					dhtmlxError.catchError("ALL",my_error_handler);
		
		if(!$defined($('liSubjectsTree'))) return;

		// subjects tree
		subjects_tree = new dhtmlXTreeObject('subjects','100%','100%',0);
		//subjects_tree.setImagePath('/js/dhtmlxtree/imgs/csh_sindup/');
		subjects_tree.setImagePath('/skins/default/trees/');
		subjects_tree.enableSmartXMLParsing(true);

					function preventTreeDrag() {
				return false;
			}
			subjects_tree.attachEvent('onBeforeDrag', preventTreeDrag);
				//subjects_tree.attachEvent('onClick', offNodeSelect);
		subjects_tree.attachEvent('onClick', onSubjectSelect);
		subjects_tree.setStdImages('../icons/picto-folderClosed-2.gif', '../icons/picto-folderOpened-2.gif', '../icons/picto-folderClosed-2.gif');
		subjects_tree.setIconSize(16,16);

		subjects_tree.attachEvent('onXLE', function(){
			if($defined($('waitingSubjects'))){
				$('waitingSubjects').destroy();
			}
		});
					subjects_tree.loadXML('/subjects.xml');
		
		subjects_tree.setUserData(0,'name','subjects');
		TREES.push(subjects_tree);
		HTREES.set('subjects_tree', subjects_tree);

}