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 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 checkReferrerCode()
{
    var oQry = new Querystring();
    var code = oQry.get( "code", "" );

    if ( code!=null && code != "" )
    {
        document.getElementById( 'referrer_code' ).value=code;
        setCookie( 'r_code', code, 30 );
    } else {
        code=getCookie('r_code');
        if (code!=null && code!="")
            document.getElementById( 'referrer_code' ).value=code;
    }
}

checkReferrerCode();