function validate() {
  var str = document.form1.email.value;
  var isEmail = ((str.indexOf("@") != -1) && (str.indexOf(".") != -1));
  var formfield = document.form1 
  if (formfield.f_name.value.length == 0) {
    alert("Please enter a your First Name.");
    formfield.f_name.focus();
    return false;
  }
  if (formfield.l_name.value.length == 0) {
    alert("Please enter a your Last Name.");
    formfield.l_name.focus();
    return false;
  }
  if (formfield.email.length ==0){
	  alert('You must enter a valid email address to continue');
    formfield.email.focus();
	  return false; 
	}
  if (!isEmail) {
    alert("Sorry, " + str + " is an invalid email address!");
    formfield.email.select();
    formfield.email.focus();
    return false;  
  }     
  if (formfield.address1.value.length == 0) {
    alert("Please enter your Address.");
    formfield.address1.focus();
    return false;
  }  
  if (formfield.city.value.length == 0) {
    alert("Please enter your City.");
    formfield.city.focus();
    return false;
  }
  if (formfield.zip.value.length == 0) {
    alert("Please enter your Zip / Postal Code.");
    formfield.zip.focus();
    return false;
  }
  if (formfield.zip.value.length < 5) {
    alert("Please enter at least 5 digits for your Zip / Postal Code.");
    formfield.zip.focus();
    return false;
  }  
  if (formfield.phone.value.length == 0) {
    alert("Please enter your Phone Number so we can contact you");
    formfield.phone.focus();
    return false;
  }
  if(formfield.referred_by.options[formfield.referred_by.selectedIndex].value=="") {
    alert("Please tell us how you heard about us.");
    formfield.referred_by.focus();
    return false;
  }    
 }