php与mysql建立连接并执行SQL语句的代码

<?php 
$conn = mysql_connect("localhost","root","") or die ("wrong!"); 
$sel=mysql_select_db("mydb",$conn); 
$sql="INSERT INTO `mydb`.`test` ( 
`id` , 
`uid` , 
`regdate` , 
`remark` 
) 
VALUES ( 
'', 'php200', now( ) , 'dddd' 
) "; 
$que=mysql_query($sql,$conn); 
if($que) 
echo"true"; 
else 
echo "wrong"; 
?>