function CheckEmail(str) {
var at="@";
var dot=".";
var lat=str.indexOf(at);
var lstr=str.length;
var ldot=str.indexOf(dot);
if (str.indexOf(at)==-1) {
return false;
}
if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr) {
return false;
}
if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr) {
return false;
}
if (str.indexOf(at,(lat+1))!=-1) {
return false;
}
if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot) {
return false;
}
if (str.indexOf(dot,(lat+2))==-1) {
return false;
}
if (str.indexOf(" ")!=-1) {
return false;
}
return true;
}



function validatePhone(fld) {
var error = "";
var stripped = fld.value.replace(/[\(\)\.\-\ ]/g, '');
if (fld.value == "") {
error = "You didn't enter a phone number.\n";

}
else if (isNaN(parseInt(stripped))) {
error = "The phone number contains illegal characters.\n";

}
else if (!(stripped.length >= 8 && stripped.length <= 15)) {
error = "The phone number is the wrong length.\n";

}
return error;
}

function Validate() {
if(document.getElementById('user').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Username is required, please enter a valid username!");
document.getElementById('user').focus();
return false;
}
if(document.getElementById('pass').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Password is required, please enter a valid password!");
document.getElementById('pass').focus();
return false;
}
if(document.getElementById('confirmpass').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Please re-enter your password in the Confirm Password field!");
document.getElementById('confirmpass').focus();
return false;
}
if(document.getElementById('firstname').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Please enter your First Name!");
document.getElementById('firstname').focus();
return false;
}
if(document.getElementById('surname').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Please enter your Surname!");
document.getElementById('surname').focus();
return false;
}
if(!CheckEmail(document.getElementById('email').value)) {
alert("Invalid E-mail Address!");
return false;
}
if (validatePhone(document.getElementById('Phone')) != "") {
alert("Phone is required, please enter a valid phone number!");
return false;
}

if(document.getElementById('DOB').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Please enter your Date of Birth!");
document.getElementById('DOB').focus();
return false;
}


if(document.getElementById('Postcode').value.replace(/^\s+|\s+$/g, '') == "") {
alert("Postcode is required, please enter a valid postcode!");
document.getElementById('Postcode').focus();
return false;
}

return true;
}