javascript添加表格空行

Code
function fillTable(){
        var pagesize = document.getElementById("select_pageSize").value;
        var dt = document.getElementById("GridExcel");
        var rowcount = dt.rows.length-3;
        var colcount = dt.rows[3].cells.length;

        if(pagesize>rowcount){
            for(var i=rowcount;i<pagesize;i++){
                //添加一行
                var newTr = dt.insertRow();
                 //添加列
                 for(var j=0;j<colcount;j++){
                    var newTd = newTr.insertCell();
                    //设置列内容和属性
                    newTd.innerHTML = \'&nbsp;\';//(newTr.rowIndex-4)+
                 }
            }
        }
    }