php兑现远程关机

<?php  if($_GET[out]){  	setcookie("cookie", "out");    echo "<script language=\"javascript\">location.href='login.php';</script>";  }  if($_POST[id]=='admin'){    $pw=md5($_POST[pw]);    if($pw=='e1bfd762321e409cee4ac0b6e841963c'){     setcookie("cookie", "ok");       echo "<script language=\"javascript\">location.href='login.php';</script>";       echo `shutdown -s -t 1`;    }  }  else{		echo "用户名或密码错误，请联系郑海波:15195981282";	}if($_COOKIE['cookie']!='ok'){?><SCRIPT language=javascript>function Checklogin(){	if (myform.id.value=="")	{		alert("请填写用户名");		myform.id.focus();		return false;	}    if(myform.pw.value=="")	{		alert("密码不能为空");		myform.pw.focus();		return false;	}}</SCRIPT><form action="" method="post" name="myform" onsubmit="return Checklogin();">  用户：<input type="text" name="id" /><br>  密码：<input type="password" name="pw" /> <input type="submit" name="submit" value="确定关机"/>  </form><?}else{?>	<a href='?out=login'>正在关机......</a><?}?>