Returning Number Of Records Found In Query

I am trying to return the number of records found by the query but keep seeing -1 in label1. This query should return many records.

         sub findcustomers(sender as object,e as eventargs)
            dim connection1 as sqlconnection=new sqlconnection(...)
            dim q1 as string="select * from tblcustomers where store='65'"
            dim command1 as sqlcommand=new sqlcommand(q1,connection1)
            dim a as integer
            command1.connection.open()
            a=command1.executenonquery()
            label1.text=a.tostring()
            command1.connection.close()
         end sub

What am I doing wrong?