function readCookie(name) {
  var cookiename = name + "=";
  var ca = document.cookie.split(';');

  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    
    while (c.charAt(0)==' ') 
      c = c.substring(1,c.length);

    if (c.indexOf(cookiename) == 0) 
      return c.substring(cookiename.length,c.length);
  }
  
  var empty = '';
  return empty;
}

function checkForm(form){	
  var ref_url;
  ref_url = readCookie('ref');	
  
  ff = document.createElement("INPUT");
  ff.type = "hidden";
  ff.name = "ref";
  ff.value = ref_url;
  
  form.appendChild(ff);	
  form.submit();
}