Php Error Pls Help

<?php
include('conn.php') 
do($_POST['register']);
<form action="register.php" method="post"
{
	$username=$_POST['username'];
	$password=$_POST['password'];
	$password2=$_POST['password2'];
	$date_now=date('Y-m-d');
	if($password==$password2 ){
		$query = "SELECT * FROM Member Where ID='$UID'";
		$result_ = mssql_query($query);
		$numRows = mssql_num_rows($result_); 
		if($numRows==0){
			$sql="dbo.up_CreateMemberAccount '0','$ID','$password','1','$date_now'";
			$result = mssql_query($sql);
			if($result)
			  echo"<script type='text/javascript'> alert(' Registration Successful. ');</script>";
			else
				echo"<script type='text/javascript'> alert(' Username is taken ');</script>";
		}else{
				echo"<script type='text/javascript'> alert(' Username already exists ');</script>";
		}
	}else{
		echo"<script type='text/javascript'> alert(' Passwords does not match  ');</script>";
	}
}