[Rabeea Qbaha]

كود :

'function to check if the user is already exists
   Public Function UserEx(ByVal id_number As String) As Boolean
       Dim correct_version As Boolean = False
       Dim command As New SqlCommand("SELECT eid FROM Employees WHERE eid = @eid", SQL.conn)
       command.Parameters.AddWithValue("@eid", id_number)
       SQL.conn.Open()
       Using reader As SqlDataReader = command.ExecuteReader
           While reader.Read
               If IsDBNull(reader("eid")) Then
                   correct_version = False
               Else
                   correct_version = True
               End If
           End While
       End Using
       command.Parameters.Clear()
       SQL.conn.Close()
       Return correct_version
   End Function

كود :

If UserEx(emp_id_txt.Text) = True Then
           
         
           
         
           End If