function checkForm() {
 document.form.Email.value = " " + document.form.Email.value;

  if (document.form.Name.value == "") {                      // this part of the script is
      alert('The Name field is empty!'); return false; }     // related to the Name field

  mail = document.form.Email.value;                            // this part of the script is
  if ((mail.indexOf('@') == -1) || (mail.indexOf('.') == -1)) {
      alert('The E-mail address is invalid!'); return false; } // related to the E-Mail field

  if (document.form.Query.value == "") {                       // this part of the script is
      alert('The Comments / Query field is empty!'); return false; }
  if (document.form.Query.value.length > 250) {
      alert('The Comments / Query is too long!'); return false; } // related to the Comments field
               //  the code prevents users from typing in more than 250 characters in the comment
               //  field. The # can be modified by typing in any number instead of 250. If this
               //  feature is not needed just delete the 2 lines in the code above.

  document.form.AppName.value = navigator.appName;
  document.form.AppVersion.value = navigator.appVersion;
  document.form.Resolution.value = window.screen.width + " X " + window.screen.height;

  window.setTimeout("history.back(-1)",2000);
  return true;
 }