var form = "";
var submitted = false;
var error = false;
var error_message = "";

function check_input(field_name, field_size, message) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;

    if (field_value == '' || field_value.length < field_size) {
      error_message = error_message + "* " + message + "\n";
      error = true;
    }
  }
}

function check_form(form_name) {
  if (submitted == true) {
    alert("This form has already been submitted. Please press Ok and wait for this process to be completed.");
    return false;
  }

  error = false;
  form = form_name;
  
//  error_message = "Errors have occured during the process of your form.\n\nPlease make the following corrections:\n\n";
//  check_input("email_address", 6, "Your E-Mail Address must contain a minimum of 6 characters.");

//  check_input("name", 2, "Your Name must contain a minimum of 2 characters.");
//  check_input("pnumber", 3, "Your Last Name must contain a minimum of 3 characters.");

  chk_value = form.elements["email_address"].value ;
  ret = checkEmail( chk_value ) ;

  if (ret == false) {
//    alert(error_message);
    return false;
  } else {
    submitted = true;
    return true;
  }
}

function checkEmail(MyValue) {
  if ( MyValue.indexOf('@') <= 0 || MyValue.indexOf('.') == -1 || MyValue.length < 6 ||
       MyValue.match(/[!"#$%&'\(\)=\\|,:;^\[\]\{\}`*?+>< ]/) 
      ){
         alert("Input email value is invalid.");
         return false;
  }
  return true;
}