下面是test.html的一段代码，为什么执行test1()，提示下载excel文件，而test2()打开excelexport.php之后，没有提示保存就自动关闭了？

<input type="button" value="btn1" onclick="test1()"/>
<input type="button" value="btn2" onclick="test2()"/>
<script language="javascript" type="text/javascript">
    function test1() {
        window.open("excelexport.php");
    }
    function test2() {
        window.setTimeout(test1,1);
    }
</script>


excelexport.php的代码:
<?php
header("Content-Type:application/force-download");
header("Content-Type:application/vnd.ms-execl");
header("Content-Type:application/octet-stream");
header("Content-Type:application/download");
header('Content-Disposition:attachment;filename="charging.xls"');
header("Content-Transfer-Encoding:binary");
?>
--
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