// JavaScript Document
function rolloverButton (id) {
  if (document.getElementById) {
    var element_id = document.getElementById(id);
    var overPosition = element_id.className.indexOf("Over");
    
    if (overPosition == -1)
    {
    	element_id.className = element_id.className + "Over";
    }
    else
    {
    	element_id.className = element_id.className.substr(0,overPosition);
    }
 
  }
  }