datagrid小tip(二):拼接多层表头

<script language="javascript">
        //初始化表头，生成双层表头    
        window.onload = function()
        {
            var obj = document.getElementById("DataGrid1");            
            if(obj != undefined)
            {
                var row=obj.insertRow(0);
                row.className = "headStyle";
                var Cell1 = row.insertCell();
                Cell1.innerText = "单位";
                Cell1.rowSpan = 3;
                
                var Cell2 = row.insertCell();
                Cell2.innerText = "在职";
                Cell2.colSpan=4;                
                
                var Cell3 = row.insertCell();
                Cell3.innerText = "退休";
                Cell3.colSpan = 4;
                
                var Cell4 = row.insertCell();
                Cell4.innerText = "合计";
                Cell4.colSpan = 2;    
                Cell4.rowSpan=2;    
                
                var row1=obj.insertRow(1);
                row1.className = "headStyle";
                
                
                var Cell5 = row1.insertCell();    
                Cell5.innerText = "<=45";    
                Cell5.colSpan = 2;        
                var Cell6 = row1.insertCell();    
                Cell6.innerText = ">45";    
                Cell6.colSpan = 2;    
                
                var Cell7 = row1.insertCell();    
                Cell7.innerText = "<=65";
                Cell7.colSpan = 2;        
                var Cell8 = row1.insertCell();    
                Cell8.innerText = ">65";    
                Cell8.colSpan = 2;        
                
                obj.rows[2].deleteCell(0);    
                
            }
        }
        </script>

datagrid的绑定列的表头可以正常写,然后用Javascript画出需要的多层表头.这段代码的最重要的一步就是对是否存在datagrid的判定,因为如果后台代码不是开始load页面的时候就绑定datagrid并显示的话,这段代码会报错.