var fieldstocheck = new Array();
    fieldnames = new Array();

function checkform() {
  for (i=0;i<fieldstocheck.length;i++) {
    if (eval("document.subscribeform.elements['"+fieldstocheck[i]+"'].value") == "") {
      alert("Please enter your "+fieldnames[i]);
      eval("document.subscribeform.elements['"+fieldstocheck[i]+"'].focus()");
      return false;
    }
  }
  return true;
}
function addFieldToCheck(value,name) {
  fieldstocheck[fieldstocheck.length] = value;
  fieldnames[fieldnames.length] = name;
}