function mouseover() {
        var ButtonName = event.srcElement.name;
        var ExprName = 'btn';
        var string1 = ButtonName.search(ExprName);
        var bname = ButtonName.substr(string1);
        event.srcElement.src = './newimages/buttons/' + bname + '_mo.gif';
    }      
   function mouseout() {
       var ButtonName = event.srcElement.name;
       var ExprName = 'btn';
       var string1 = ButtonName.search(ExprName);
       var bname = ButtonName.substr(string1);
       event.srcElement.src = './newimages/buttons/' + bname + '.gif';
   }