PHP:Header Redirect无法重定向到其他文件夹中的文件.当我试图重定向到包含代码的文件所在的同一目录之外的

Header Redirect不起作用。代码在iar-calculator.php文件下，代码适用于第二个elseif，但由于其他两个文件位于不同的目录或文件夹中。我试过使用../folder name/page.php，`folder-name/page.php ``。这两种方法在我的情况下都不起作用。我该怎么修？感谢

//重定向

if(isset($_POST['cmd_submit'])){
    if(($_POST['tire'] == "rear") && ($_POST['tractor'] == "2wd" || $_POST['tractor'] == "4wd")){
         //redirect here
         header('location:iar-calculator.php');
    }
    elseif(($_POST['tire'] == "rear") && ($_POST['tractor'] == "mfwd")){
         //redirect here
         header('location:index.php');
    }
    elseif(($_POST['tire'] == "front") && ($_POST['tractor'] == "2wd" || $_POST['tractor'] == "4wd")){
         //redirect here
         header('location:front/index.php');}
     elseif(($_POST['tire'] == "front") && ($_POST['tractor'] == "mfwd")){
         //redirect here
         header('location:front/iar-calc-rear.php');
    }
    else{
    }
}

//HTML代码

    <form method="post" style="padding: 10px 0px 10px 5px;">
     <select name="tire" style="width:100px;display:inline;height: 30px;" class="first">
      <option  value="">Select</option>
      <option  value="rear">Rear Tire</option>
      <option  value="front">Front Tire</option>
  </select> 
  <select name="tractor" style="width:100px;height: 30px;display:inline" class="second" disabled>
      <option value="">select Type</option>
      <option value="2wd">2WD</option>
      <option value="mfwd">MFWD</option>
      <option value="4wd">4WD</option>
 </select>  
 <input type="submit" value="Go" name="cmd_submit" />

?>