怎么改变html里file的按钮的值

怎么改变html里file的按钮的值
//==================================
<script>
function UpLoadForm_Validator(pUpLoadForm)
{
if(document.all.UpLoadFile.value=="")
{
window.confirm("请选择上传的文档!");
pUpLoadForm.UpLoadFile.focus();
return false;
}
var strFileFormat=pUpLoadForm.UpLoadFile.value.match(/^(.*)(/.)(.{1,8})$/)[3];//检查上传文件格式
strFileFormat=strFileFormat.toUpperCase();
if(strFileFormat=="DOC"||strFileFormat=="DOT")
{
}
else
{
window.confirm("只能上传.Doc和.Dot,请重新选择!");
return false;
}
return true;
}

</script>
<form method="POST" enctype="multipart/form-data" action="" onsubmit="return UpLoadForm_Validator(this)" laguage="JavaScript" name="UpLoadForm">
<input type="file" name="UpLoadFile" id="UpLoadFile" style="visibility:hidden;">
<input type=button onclick="UpLoadFile.click();">
<input type="submit" value="上传" name="UpLoadButton">
</form>

//===========================
<input type=text name=text1>
<input type="file" name="UpLoadFile" id="UpLoadFile" style="visibility:hidden;">
<input type=button onclick="SelectFile()" value=_浏_览_>
<script>
function SelectFile()
{
UpLoadFile.click();
text1.value = UpLoadFile.value
}
</script>