//function to check valid email address
function isValidOpt(strEmail){
  validRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
  strEmail = document.opt_form.email.value;

   // search email text for regular exp matches
    if (strEmail.search(validRegExp) == -1) 
   {
      alert('A valid e-mail address is required.');
      return false;
    } 
    return true; 
}


//function that performs all functions, defined in the onsubmit event handler

function check_opt(form){
	if (isValidOpt(form.email)){
		  return true;
	}
return false;
}