我有一个针对隐藏iframe的表单。这在IE上运行正常，但是在FireFox中提交表单时没有任何React。没有提交。知道是什么导致了差异吗？
表单和iframe如下所示：

<form name="dial" method="get" target="callout" action="/cgi-bin/make_call.php">    
    &nbsp;&nbsp;&nbsp;
    <input type="text" style="width:190px;" id="calling" name="calling" />
    <input type="hidden" name="caller" value="<? echo $extension; ?>">
    &nbsp;&nbsp;
    <input type="submit" name="search" class="btn btn-info btn-large" style="width:65px; height: 30px; position:relative;top:-5px;left:-2px; padding:0.2em; " value="Dial" />
</form>
<iframe name="callout" width="0" height="0"></iframe>

正在加载的页面为：

<?
$caller = $_GET['caller'];
$calling = $_GET['calling'];

//Clean the non numbers out of our string
$calling = preg_replace("/[^0-9]/","",$calling);

//If we are dialing a 7 digit number add a 9 to access an outside line
if(strlen($calling) == 7){
    $calling = "9".$calling;
    }

//If we are dialing a 10 digit number add 9 and 1 to access outside line
if(strlen($calling) == 10){
    $calling = "91".$calling;
    }

//If we are dialing a 11 digit number add 9 to access outside line
if(strlen($calling) == 10){
    $calling = "9".$calling;
    }

header("Location: http://XX.X.XX.XX:8070/ShoreTelWebSDK/REST/DialNumber?callingExtension=$caller&destinationNumber=$calling");  
?>

如果我改变脚本来输出一个测试消息，并以一个可见的iframe为目标，我仍然在FireFox中一无所获，但它在Internet Explorer中同样工作得很完美。