js取得gridview中checkbox选中的值

测试好半天，才出来，checkbox在第一列，
       for( i=1;i<document.all.GVmain.rows.length;i++)
         {
            var cb=document.all.GVmain.rows(i).cells(0).children(0);
            if(cb.checked)
            {
                 temp0=document.all.GVmain.rows(i).cells(1).innerText;
                 temp1=document.all.GVmain.rows(i).cells(5).innerText;
                 temp2=document.all.GVmain.rows(i).cells(6).innerText;
              }
         }