datagridview values into excel

Question

  hai,

 i have a form with datagridview(have 5 row values)  and 2 buttons. when we click the 1st button we want to create the excel sheet according to datagridview headers. and when we click the 2nd button we want to update(using update query or not) the existing excelsheet according to datagridview values. plz help.