Adding Dynamic row to Row

I have written the following code in javascript. This code is working fine in FireFox but not in IE 7.
Need help so that it should  also work fine in IE7.
Thanks. 

var repeater= document.getElementById('<%=repeater.ClientID %>');

        var obj = result;

        var newRow = document.createElement("tr");

        var newCell = document.createElement("td");
        var ctrlInputHid = document.createElement("input");
        ctrlInputHid.type = "hidden";
        ctrlInputHid.setAttribute("value", obj.ID);
        newCell.appendChild(ctrlInputHid);
        ...