function resetLeftBar(myTab, maxId) {
//window.alert(myTab.nodeType);
 for (var Id = 1; Id <= maxId; Id++) {
   var myRow = myTab.getElementsByTagName("tr")[Id - 1];
   var myNode = myRow.getElementsByTagName("td")[0];
   var myAncor=myNode.getElementsByTagName("a")[0];
     var node_class = document.createAttribute("class");
       node_class.nodeValue = "grey";
       myAncor.setAttributeNode(node_class);
       // window.alert(myAncor.nodeType);
 }
}

function setLeftButton(Id, maxId) {
var myTab = document.getElementById("leftnav2");
resetLeftBar(myTab, maxId);
if (Id == 0) return 0;
var myRow = myTab.getElementsByTagName("tr")[Id - 1];
var myNode=myRow.getElementsByTagName("td")[0];
var myAncor=myNode.getElementsByTagName("a")[0];

var node_class = document.createAttribute("class");
 node_class.nodeValue = "red";
 myAncor.setAttributeNode(node_class);
return 0;
}