[RESOLVED] formatting grid column

Like if want to format my grid with the following columns itemid, itemdescription, qty,cost, total

formatgridcolumn flexgrid1, 1, 3, "#,###.##"
formatgridcolumn flexgrid1, 1, 4, "#,###.##"
formatgridcolumn flexgrid1, 1, 5, "#,###.##"

But I am getting runtime error 13, type mismatch. Where could be the cause of the error ?

I am using msflexgrid.