make gridview editable onasp:button server control click

Question

Hi,
I have a textbox and button control. User will enter number in textbox and click button. That much number of rows should get added to gridview and gridview should be in edit mode at the same time. I have written the code for adding row but I cant make the gridview editable on the button click of the same button. How to make gridview editable onasp:button server control click