.NET DataGrid Control

Hi, When some control in a page modifies the data displayed in a datagrid (through an sql update query, of course), how do I refresh the datagrid? Binding the datagrid doesn't seem to work. Re-binding the datasource doesn't work. Binding the datasources also doesn't help. ...

I have a button on my form which is enabled when the user selects a record in the datagrid (I do not want an edit button for each record in the grid). How can I force the datagrid into edit mode when the user clicks on this ...

i am new to asp.net i find when using edit template to edit record with "null field", it fail it is ok when the record has no null data field. how should i do?  Thanks tony ...