js怎么清空tr

nbsp;HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">


<title> New Document </title><meta><meta><meta><meta><script>// Example: obj = findObj("image1");
function findObj(theObj, theDoc)
{ 
var p, i, foundObj; 
if(!theDoc) theDoc = document; 
if( (p = theObj.indexOf("?")) > 0 && parent.frames.length) 
{  theDoc = parent.frames[theObj.substring(p+1)].document;  theObj = theObj.substring(0,p); } if(!(foundObj = theDoc[theObj]) && theDoc.all) foundObj = theDoc.all[theObj]; for (i=0; !foundObj && i < theDoc.forms.length; i++)   foundObj = theDoc.forms[i][theObj]; for(i=0; !foundObj && theDoc.layers && i < theDoc.layers.length; i++)   foundObj = findObj(theObj,theDoc.layers[i].document); if(!foundObj && document.getElementById) foundObj = document.getElementById(theObj);  return foundObj;
}

//删除指定行
function DeleteSignRow(rowid){
var signFrame = findObj("SignFrame",document);
var signItem = findObj(rowid,document);
alert(rowid);
//获取将要删除的行的Index
var rowIndex = signItem.rowIndex;
  
//删除指定Index的行
signFrame.deleteRow(rowIndex);
  
//重新排列序号，如果没有序号，这一步省略
for(i=rowIndex;i<signFrame.rows.length;i++){
signFrame.rows[i].cells[0].innerHTML = i.toString();
}
}
//清空列表
function ClearAllSign(){
if(confirm(&#39;确定要清空所有参与人吗？&#39;)){
var signFrame = findObj("SignFrame",document);
var rowscount = signFrame.rows.length;
  
//循环删除行,从最后一行往前删除
for(i=rowscount - 1;i > 0; i--){
  signFrame.deleteRow(i);
}
  
//重置最后行号为1
var txtTRLastIndex = findObj("txtTRLastIndex",document);
txtTRLastIndex.value = "1";
  

}
}
</script>
  

<div>
<table>
       <tr>
        <td>序号</td>
        <td>用户姓名</td>
        <td>电子邮箱</td>
        <td>固定电话</td>
        <td>移动手机</td>
        <td>公司名称</td>
        <td> </td>
       </tr>
    </table>
  </div>
  <div>
    <input> 
   <input>
   <input>
  </div>