function ob_t2_UnselectAllNodes()
{
    ob_sn2 = "";
    var oTempNode = ob_getFirstNodeOfTree();    
    while(oTempNode != null)
    {        
        oTempNode.className = "ob_t2";
        var myEl2 = oTempNode.parentNode.parentNode.parentNode;
        myEl2.style.backgroundColor = 'transparent';
        
 	    oTempNode = ob_getNodeDown(oTempNode, false); 	            
    }
}