Hi
i make the dataadapter get data and view in datagridview successfully
and the same adapter let it get another table by changing the select statement and view it in another datagridview till now ok.

i have 2 update buttons every one for each table
the first dataset i call
da.update(ds1)

and the second
da.update(ds2)

i found that the second one raise exception says "Object renfrence is set to none" means that the dataadapter is no longer exists ?!

any explanation
by the way i can make both tables in one dataset and they will work. but i want explanation for this error.

thanks in advance.