实现上传（增删）多个文件的客户端写法。

<form name=form method=post enctype=multipart/form-data target=editpost ID=Form1>
<select class=TBGen name=SelectFile style=width:200></select>
<button onclick=DelFiletoSelect()>删除</button>
<span id=AffixFile>
 <span><input style=width:10 name=affixs type=file onpropertychange=AddFiletoSelect(this)></span>
</span>
</form>
<SCRIPT LANGUAGE=JavaScript>
 function AddFiletoSelect(aoFile){
　 if ((aoFile==null)||(aoFile.value==)) return;
　 var loOpts = form.SelectFile.options;
　 loOpts[loOpts.length] = new Option(aoFile.value,aoFile.uniqueID);
　 aoFile.parentElement.style.display = none;
　 var loObj = document.createElement(span);
　 loObj.innerHTML = <input style=width:10 name=affixs type=file onpropertychange=AddFiletoSelect(this)>;
　 AffixFile.insertBefore(loObj);
 }
 function DelFiletoSelect(){
  loEL = document.all(form.SelectFile.value);
  if (loEL!=null){
　 loEL = loEL.parentElement;
　 AffixFile.removeChild(loEL);
  }
  var loOpts = form.SelectFile.options;
  if(loOpts!=null&&loOpts.length>0){
　 loSel = loOpts[form.SelectFile.selectedIndex]
　 loOpts.removeChild(loSel);
  }
 }
</SCRIPT>