向GRIDVIEW头部加多选框代码

<asp:TemplateColumn HeaderText="&lt;INPUT type='checkbox' id='chkall1' name='chkall1' value='check' onclick='SelectAll2(this.checked)'&gt;">

 

 function SelectAll(obj){
       var objTR = obj.parentNode.parentNode;
       var ins = objTR.getElementsByTagName("input");      
      
       for(i = 1; i < ins.length; i ++){
           if(ins[i].type == "checkbox"){
                ins[i].checked = obj.checked;
           }
       }
    }