try this one...
you want to fist select the row you want to send data and then click the "Send" button and send data? right?
so you can do something like this..
for the CellContentClick event of datagridview add this code (make sure to declare
outside the event..then you can refer it from the button click event)
RowNo = e.RowIndex;
for the button click event
string Value = dataGridView1.Rows[RowNo].Cells.Value.ToString();
instead of giving Cells you can give column name that you have given inside " "