DataList accessing values

Hi All,


I am using a DataList, C#.  I have a DataList with a Link.  It works fine f I don't append the second parameter but when I do I get this error:


Object reference not set to an instance of an object.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Line 68:  IIDLabel1.Text = _makeId2.ToString();


Does anyone have any idea what is causing this problem?


This doesnt work::
if (e.CommandName == "select")
        {
            //string sMkeId = string.Empty;
            if (Request.QueryString["Inventory_ID"] != null && Request.QueryString["Inventory_ID"].ToString() != string.Empty)
  & ...