function setCookie(c_name,value,expiredays)
{
var exdate=new Date();
exdate.setDate(exdate.getDate()+expiredays);
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}

function getCookie(c_name)
{
if (document.cookie.length>0)
  {
  c_start=document.cookie.indexOf(c_name + "=");
  if (c_start!=-1)
    { 
    c_start=c_start + c_name.length+1; 
    c_end=document.cookie.indexOf(";",c_start);
    if (c_end==-1) c_end=document.cookie.length;
    return unescape(document.cookie.substring(c_start,c_end));
    } 
  }
return "";
}

function checkCookie() {
	var ref_name = getCookie('ref_name');
	if (ref_name != null && ref_name !="") {
		//alert(ref_name);
	} else {
		ref_name = document.referrer;
		if (ref_name==null || ref_name == "") {
			ref_name = "not specified";
		}
		setCookie('ref_name',ref_name,1);
	}	
}

function addField() {
	document.getElementById('coming_from').value = getCookie('ref_name');
}