function DeleteCookie (name) 
{ 
var exp = new Date(); 
exp.setTime (exp.getTime() - 1); 
var cval = GetCookie (name); 
document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();

var expDays = 1;
var exp = new Date(); 
exp.setTime(exp.getTime() + (expDays*24*60*60*1000));
}