js 获取gridview 点击行每个单元格的值

function getVal(){
 var obj=event.srcElement; 
            while(obj.tagName!="TR") 
            { 
                obj =obj.parentElement; 
            } 
               var a=obj.children[0].innerHTML; 
               var b=obj.children[1].innerHTML; 
               var c=obj.children[2].innerHTML; 
}