Erro message: Incorrect syntax near ','. (severity 15)

estou com esse erro ao tentar efetuar um cadastro como posso resolver 

Warning: mssql_query() [function.mssql-query]: message: Incorrect syntax near ','. (severity 15) in C:\wamp\www\register.php on line 163

Warning: mssql_query() [function.mssql-query]: Query failed in C:\wamp\www\register.php on line 163

usando sql 2005

$res = mssql_query($query);
		if($res===false) $error = "Database error. Try again";
		
		if(strlen($error)==0){
			if($site_acc_activation == 'mail'){
				mail($Email,'Registration confirmation',"Follow that link to complete you registation.\n$activation_url\n");
				$content_template = "register3.php";
			}
			else{
				$content_template = "register3_admin.php";

<?php
session_start(); 
include("./common/auth.php");
include("./common/func.php");
include("./common/config.php");
$userLogin = $user->getLogin();

include("./common/page_tree.php");

$error = "";

require('./db/db_config.php');
$link=mssql_connect($database['db_host'],$database['db_login'],$database['db_password']) or die(mssql_get_last_message());
mssql_select_db($database['db_name'],$link) or die("Database unavailable"); 

if(isset($_GET['todo'])){
	switch ($_GET['todo']) {
		case 'activate_user':
			$activation_code = $_GET['code'];
			$query = "select * from UserInfo where activation_code='$activation_code';";
			$res = mssql_query($query);
			if(mssql_num_rows($res)!=1) $error = "No user with such activation code";
			if(strlen($error)==0){
				$fetch = mssql_fetch_assoc($res);
				$query = "UPDATE UserInfo SET activation_code=NULL, MailIsConfirm=1 WHERE Account='{$fetch['Account']}'";
				mssql_query($query);
			}
			
			$brumble = '<a href="index.php">Home</a>|<a class="current" href="">Finish</a>';
			$brumble_name = "Account Activation";
			$content_template = "register4.php";
			require_once('./common/site_options.php');
			include("./templates/$site_template/index.php");
			mssql_close($link); 
			die();
		break;
	}
}

require_once('./common/site_options.php');

if(!$site_allow_registration){
	header("Location: index.php");
	die; 
}
 
if(isset($_POST['step'])) $step = $_POST['step'];
else $step = 1;
//if(isset($_REQUEST['step'])) $step = $_REQUEST['step'];
//else $step = 1;
$Account = $_POST['Account'];
$Password = $_POST['Password'];
$Password2 = $_POST['Password2'];
$NickName = $_POST['NickName'];
$FirstName = $_POST['FirstName'];
$MiddleName = $_POST['MiddleName'];
$LastName = $_POST['LastName'];
$Email = $_POST['Email'];
$Email2 = $_POST['Email2'];
$Gender = $_POST['Gender'];
$Birth_day = intval($_POST['Birth_day']);
$Birth_month = intval($_POST['Birth_month']);
$Birth_year = intval($_POST['Birth_year']);
$question_id = $_POST['question_id'];
$answer = $_POST['answer'];
	
//$Date_of_birth = "$Birth_day / $Birth_month / $Birth_year";
$Date_of_birth = "$Birth_year-$Birth_month-$Birth_day";
	
if($step == 2){
	if(empty($Account) || empty($Password) || empty($NickName) || empty($FirstName) || empty($Email) || empty($Gender) || empty($answer)) $error = "You didn't fill every fields";
	
	//echo 'err -'.$error.'-<br/>';
	if(strlen($error)==0 && $Password != $Password2) $error = "Your passwords are different";
	
	if(strlen($error)==0 && $Email != $Email2) $error = "Your E-mails are different";
	
	if(strlen($error)==0 && !ereg("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)+$", $Email)) $error = "E-mail adress failure";

	if(strlen($error)==0){
		$query = "SELECT * FROM UserInfo WHERE Account='$Account'";
		$res = mssql_query($query);
		if(mssql_num_rows($res) > 0) $error = "This account name is already taken";
	}
	
	if(strlen($error)==0){
		$query = "SELECT * FROM UserInfo WHERE Email='$Email'";
		$res = mssql_query($query);
		if(mssql_num_rows($res) > 0) $error = "This email is already in use";
	}
	
	if(strlen($error)==0){
		$query = "SELECT * FROM UserInfo WHERE NickName='$NickName'";
		$res = mssql_query($query);
		if(mssql_num_rows($res) > 0) $error = "This Nickname is already in use";
	}
	
	if(strlen($error)>0) $step = 1;
}
if($step == 3){
	if(empty($Account) || empty($Password) || empty($NickName) || empty($FirstName) || empty($Email) || empty($Gender) || empty($answer)) $error = "hacking attempt";
	
	$agree = $_POST['agree'];
	if($agree != 1) $error = "You should agree to the End User Licanse Agreement";
	if(strlen($error)>0) $step = 2;
}

switch ($step) {
	case 3:	
		$rnd_string = '';
		for($i=0;$i<50;$i++)
			$rnd_string .= strval(rand(0,9));
		$activation_code = md5($rnd_string);
		$activation_url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['SCRIPT_NAME']."?todo=activate_user&code=$activation_code";
		//$sql = "insert into `user` (`name`,`surname`,`login`,`password`,`email`,`activation_code`) values ('$name','$surname','$login','$password','$email','$activation_code');";			
		//$res = mysql_query($sql);
		
		$Account = $_POST['Account'];
		$Password = $_POST['Password'];
		$Password2 = $_POST['Password2'];
		$NickName = $_POST['NickName'];
		$FirstName = $_POST['FirstName'];
		$MiddleName = $_POST['MiddleName'];
		$LastName = $_POST['LastName'];
		$Email = $_POST['Email'];
		$Email2 = $_POST['Email2'];
		$Gender = $_POST['Gender'];
		$Birth_day = $_POST['Birth_day'];
		$Birth_month = $_POST['Birth_month'];
		$Birth_year = $_POST['Birth_year'];
		$question_id = $_POST['question_id'];
		$answer = $_POST['answer'];
		
		$query = "INSERT INTO UserInfo
           ([Account]
           ,[Birthday]
           ,[Email]
           ,[FirstName]
           ,[Gender]
           ,[LastName]
           ,[MD5PassWord]
           ,[MiddleName]
           ,[NickName]
           ,[Right]
           ,[MotherLName]
           ,[question_id]
           ,[activation_code])
     VALUES
           ('$Account'
		   ,'$Date_of_birth'
		   ,'$Email'
		   ,'$FirstName'
		   ,'$Gender'
		   ,'$LastName'
		   ,'".md5($Password)."'
		   ,'$MiddleName'
		   ,'$NickName'
		   ,1
		   ,'$answer'
		   ,$question_id
		   ,'$activation_code')";
		
		$res = mssql_query($query);
		if($res===false) $error = "Database error. Try again";
		
		if(strlen($error)==0){
			if($site_acc_activation == 'mail'){
				mail($Email,'Registration confirmation',"Follow that link to complete you registation.\n$activation_url\n");
				$content_template = "register3.php";
			}
			else{
				$content_template = "register3_admin.php";
			}
		}

		$brumble = '<a href="index.php">Home</a>|<a class="current" href="">Finish</a>';
		$brumble_name = "Account Pending Activation";
		//$content_template = "register3.php";
		//require_once('./common/site_options.php');
		include("./templates/$site_template/index.php");
	break;
	case 2:	
		$Date_of_birth = "$Birth_day / $Birth_month / $Birth_year";
		
		$brumble = '<a href="index.php">Home</a>|<a class="current" href="">Confirm</a>';
		$brumble_name = "Verify Your Account Information";
		$content_template = "register2.php";
		//require_once('./common/site_options.php');
		include("./templates/$site_template/index.php");
	break;
	case 1:
	default:
		$query = "select * from Questions";
		$question_list = mssql_query($query); 

		$brumble = '<a href="index.php">Home</a>|<a class="current" href="">Sign Up</a>';
		$brumble_name = "Account Information";
		$content_template = "register.php";
		//require_once('./common/site_options.php');
		include("./templates/$site_template/index.php");
	break;
}

mssql_close($link); 
?>