php中alert函数的用法

Alert("","function","close2",300);

function Alert($Str,$Typ="back",$TopWindow="",$Tim=100){
  echo "<script>".chr(10);
  if(!empty($Str)){
    echo "alert("Warning:\n\n{$Str}\n\n");".chr(10);
  }
  echo "function _r_r_(){";
  $WinName=(!empty($TopWindow))?"top":"self";
  switch (StrToLower($Typ)){
  case "#":
    break;
  case "back":
    echo $WinName.".history.go(-1);".chr(10);
    break;
  case "reload":
    echo $WinName.".window.location.reload();".chr(10);
    break;
  case "close":
    echo "window.opener=null;window.close();".chr(10);
    break;
  case "function":
    echo "var _T=new function('return {$TopWindow}')();_T();".chr(10);
    break;
    //Die();
  Default:
    if($Typ!=""){
      //echo "window.{$WinName}.location.href='{$Typ}';";
      echo "window.{$WinName}.location=('{$Typ}');";
    }
  }
  echo "}".chr(10);
  //為防止Firefox不執行setTimeout
  echo "if(setTimeout("_r_r_()",".$Tim.")==2){_r_r_();}";
  if($Tim==100){
    echo "_r_r_();".chr(10);
  }else{
    echo "setTimeout("_r_r_()",".$Tim.");".chr(10);
  }
  echo "</script>".chr(10);
  Exit();
}