Web Forms :: Dynamically Add Tooltip To Checkboxlist

I have a checkboxlist that I am dynamically creating from a sql database I also have the tooltips stored in the same table. After my checkbox binds I am trying to dynamically add the tooltips but it will not add them. Here is the code I am trying to run this would be great.

var c = from f in dc.sp2_columns
orderby f.Name
select f;
cblcolumns.DataSource = c;
cblcolumns.DataTextField = "Name";
cblcolumns.DataValueField = "column_name";
cblcolumns.DataBind();
GridView gv = new GridView();
gv.DataSource = c;
gv.DataBind();
int i = 0;
foreach (GridViewRow grvRow in gv.Rows)
{
cblcolumns.Items[i].Attributes.Add("ToolTip", grvRow.Cells[2].Text);
cblcolumns.ToolTip = grvRow.Cells[2].Text;
i++;
}