有个类似的例子,楼主可以做个参考
<script language="vbscript">
function addfile()
dim str
str="<table>"
if not IsNumeric (window.form1.filenum.value) then window.form1.filenum.value =1
for i=1 to window.form1.filenum.value
str=str&"<tr><td valign='middle'>文件"&i&":</td><td><input type='file' name='file"&i&"' class='tx1' value size='20'></td></tr>"
next
window.uptd.innerHTML =str&"</table>"
end function
</script>
<form name="form1" method="post" action="">
<input name="filenum" class="tx2" value="1" size="4">
个文件
<div id="uptd"> </div></td>
<input type="button" name="Button" class="bt" onClick="addfile" value="设 定">
</form>