function checkemail() { 
    xmlhttp.open("GET", 'includes/checkemail.php?email='+document.form1.emailaddress.value); 
xmlhttp.onreadystatechange = function xml() { 
     if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { 
bit = xmlhttp.responseText;
if (bit) {
alert ('Your email address is already registered on our database : '+bit+' : '+document.form1.emailaddress.value);
document.form1.emailaddress.focus();
return false;
} else {
checkcode() 
}
      } }
    xmlhttp.send(null); 
return false;
}
function checkcode() {
var code = document.form1.code.value.toLowerCase();
if (!document.form1.emailaddress.value) {
alert (' Please enter your email address');
document.form1.emailaddress.focus();
return false;
}
else if (code != '') {
alert (' You have entered the code incorrectly');
return false;
} else {
document.forms[0].submit();
return true;
}
}