var text;

function GetCookie (name) {  
 var arg = name + "=";  
 var alen = arg.length;  
 var clen = document.cookie.length;  
 var i = 0;  
 while (i < clen) {    
 var j = i + alen;    
 if (document.cookie.substring(i, j) == arg)      
 return getCookieVal (j);    
 i = document.cookie.indexOf(" ", i) + 1;    
 if (i == 0) break;   
 }  
 return null;
}

function getCookieVal(offset) {
var endstr = document.cookie.indexOf (";", offset);
if (endstr == -1)
endstr = document.cookie.length;
return unescape(document.cookie.substring(offset, endstr));
}

var source = GetCookie('adv');

if (source != null)
	  text='<input type="hidden" name="hear_about" value="' + source + '">';
else
	  text='';

document.write(text);