php 删除数据

<?php
$con = mysql_connect("localhost","root","") or die("error");
$mysql = mysql_select_db("monkey",$con);
$sql = "delete from rote where id <=4";
//$sql = "delete from rote where id=‘".$id."‘";
mysql_query($sql,$con);
$row = mysql_affected_rows(); //返回影响行数
echo $row."\n";
if($row > 0){
   echo "删除成功";
}else{
   echo "删除失败";
}
mysql_close();
?>