var highlightcolor="lightyellow";
var ns6=document.getElementById&&!document.all;
var previous='';
var eventobj;
//Regular expression to highlight only form elements
var intended=/INPUT|TEXTAREA|SELECT|OPTION/;
//Function to check whether element clicked is form element
function checkel(which){
if (which.style&&intended.test(which.tagName)){
if (ns6&&eventobj.nodeType==3)
eventobj=eventobj.parentNode.parentNode;
return true;
}
else
return false;
}

//Function to highlight form element
function highlight(e){
eventobj=ns6? e.target : event.srcElement;
if (previous!=''){
if (checkel(previous))
previous.style.backgroundColor='';
previous=eventobj;
if (checkel(eventobj))
eventobj.style.backgroundColor=highlightcolor;
}
else{
if (checkel(eventobj))
eventobj.style.backgroundColor=highlightcolor;
previous=eventobj;
}
}