I have a datagrid in which data are binded to it dynamically from database.and i have a button on click of that button i want to export all data of datagrid in excel how can we do that.If you have some code sample please help.

I have a datagrid in which data are binded to it dynamically from database.and i have a button on click of that button i want to export  all data of datagrid in excel how can we do that.If you have some code sample please help.