it didnt work, when i run it an error occured object refrence not set to an instance of object.

Hello,

This is a generic error message that most probably is not directly related to the tooltips. Can you please paste the complete stack trace and any relevant source code, so we can advise further?

Thanks.

 public virtual CellTitleMode TitleMode
    {
       get
      {
       }
     set
      {
       }
    }

protected void uwgFilterRslts_InitializeRow(object sender, Infragistics.WebUI.UltraWebGrid.RowEventArgs e)
   {
      e.Row.Cells.FromKey("Skills").TitleMode = CellTitleMode.Always;
       e.Row.Cells.FromKey("Skills").TitleMode = CellTitleMode.Always;
      
   }

i wrtite my code like this i didnt know whether its correct or not

Hello,

You do not need the first property declration (CellTitleMode), this is something that is present in the Infragistics assemblies. Null reference means that for some reasons an object does not have a refremce. e..g e.Row.FromKey("Skills") is null (not such column, etc).

It is really hard to tell - I suggest placing a breakpoint and using a debugger to figure this out.