防止表单按钮多次提交

1.

<form name=fm method="POST" action="/"><p>按钮变灰</p>name: <input type="text" name="name"/><input type="button" value="提交" οnclick="javascript:{this.disabled=true;document.fm.submit();}"></form>

2.

<form name=fm method="POST" action="/" >  <input type="submit" name="Submit" value="提交" id="submitId" οnclick="submit();">  
</form>  
<script language="javascript">  function submit()  {  var submitId=document.getElementById('submitId');  submitId.disabled=true;  document.fm.submit();  setTimeout("submitId.disabled=false;",3000); //代码核心在这里，3秒还原按钮代码  
}  
</script>