How to insert and update in GridView in single button click

Hello Sir,
I have gridview ,i insert the News in insert button then show data in gridview if
i want modify link button click then news fill in textbox and we modify then insert the
same id(Column)save
plz help me urgent
Example
Id News Modify(Linkbutton)
1 xyz Modify

News [textbox]
insert [button]
if i modify news then data come in textbox then i insert same id