function popupform(myform, windowname, emailAddress)
{
  var email = document.getElementById(emailAddress);
  if (email) {
    if (validate_email(email.value || '')) {
      window.open('', windowname, 'height=800,width=1000,scrollbars=yes');
      myform.target = windowname;
      return true;
    } else {
      alert('Please enter a valid email address.');
    }
  }
  return false;
}

function validate_email(email_address) {
  var reg = /^[A-Za-z0-9_\-\.]+\@[A-Za-z0-9_\-\.]+\.([A-Za-z]{2,4})$/;
  var domain = /^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/i;
  reg.lastIndex = 0;
  domain.lastIndex = 0;

  var m = reg.exec(email_address);
  if (m) {
    m = m[1];
    if (m.length == 2 || (m.length > 2 && m.match(domain))) {
      return true;
    }
  }
  return false;
}

function checkField(input){
	if(input.value == ""){
		input.value = "Enter your email address"
	} else if (input.value == "Enter your email address"){
		input.value = "";	
	}

}

function enableField(form)
{

form.submit.disabled=false;
}