>I am using a combo box in the grid.
>Now if I want to remove that and set it the currentcontrol again to text1 then the combo box is not getting displayed and the text box is coming as normal. That is ok. But if I want to DELETE that combo box then what is the solution ?

Select the combo in the property sheet, then click on the column in the grid (not the header) then press the delete key on the keyboard.