tab.insertRow()怎么加背景颜色css样式

 function addAttachment(fileName, fileSize){
        var tab = document.all("tabAttachment_new");
        var oRow = tab.insertRow();
        for (i = 0; i < 4; i++){
            oRow.insertCell();
            oRow.cells[i].style.cssText="background-color:FFFFFF";
        }
        oRow.cells[0].innerHTML = ++totalAttachment_new;
        oRow.cells[0].align = "center";
        oRow.cells[1].innerHTML = fileName;
        oRow.cells[2].innerHTML = fileSize;
        oRow.cells[3].innerHTML = "<a href='#' onclick='deleteAttachment();'>删除</a>";
    }
   
    function rewriteIndex(target){
        var tab = document.all("tabAttachment_" + target);
        var oRow;
        eval("totalAttachment_" + target + " = 0");
        for (i = 1; i < tab.rows.length; i++){
            oRow = tab.rows[i];
            oRow.cells[0].innerHTML = i;           
            eval("totalAttachment_" + target + " = i");
        }
    }
   
    function delAttachment(index, target){
        var tab = document.all("tabAttachment_" + target);
        tab.deleteRow(index + 1);
        rewriteIndex(target);
    }
   
    function deleteAttachment(){
        event.returnValue = false;       
        var index = parseInt(event.srcElement.parentElement.parentElement.cells[0].innerText);
        uploadFrame.location = "editupload.do?action=removeBenefit&index=" + (index - 1);
    }
   
    function deleteAttachmentdata(id){
        if (!confirm("您确定要删除吗?")){
            return;
        }
       
        var index = parseInt(event.srcElement.parentElement.parentElement.cells[0].innerText);
        uploadFrame.navigate("editupload.do?action=removedata&index=" + (index - 1) + "&attID=" + id);
    }