// form validation function //
function validateform(signup_form) {

  var first_name = signup_form.firstName.value;
  var last_name = signup_form.lastName.value;
  var email = signup_form.email.value;
  var emailRegex = /^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/;

  var error_p = document.all.signup_error;
  var error_str = "";
 
  if(email == "") {
    error_str += "<br /> - Please enter your email address";
  } else {
    if(!email.match(emailRegex)) {
       error_str += "<br /> - You have entered an invalid email";
    }
  }
 
  if(!first_name) {
    error_str += "<br /> - Please enter your first name";
  }

  if(!last_name) {
    error_str += "<br /> - Please enter your last name";
  }

  if (error_str != "" && error_p) {
    error_p.innerHTML = "There was one or more errors with the form:"+error_str+"<br />";
    return false;
  } else {
    return true;
  }
}