Record not Updating UPDATE Command, MS Access

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

       'INSERT record
       Connect()

       sql = "SELECT (sname) FROM tblsample WHERE sname = @sname"
       cmd = New OleDbCommand(sql, conn)

       cmd.Parameters.Add(New OleDbParameter("@sname", OleDbType.VarChar, 255)).Value = TextBox1.Text

       Dim rec = cmd.ExecuteScalar

       If rec = TextBox1.Text Then
           MessageBox.Show("Name already exist.", "", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
           Exit Sub
       End If

       conn.Close()
       conn.Dispose()
       cmd.Dispose()

       Try

           Connect()

           Trans = conn.BeginTransaction

           sql = "INSERT INTO tblsample(sname,contact) VALUES(@sname,@contact)"

           cmd = New OleDbCommand(sql, conn, Trans)

           cmd.Parameters.Add(New OleDbParameter("@sname", OleDbType.VarChar, 255)).Value = TextBox1.Text

           cmd.Parameters.Add(New OleDbParameter("@contact", OleDbType.VarChar, 255)).Value = TextBox2.Text

           cmd.ExecuteNonQuery()

           Trans.Commit()

           conn.Close()
           conn.Dispose()
           cmd.Dispose()

           MessageBox.Show("Saved.", "", MessageBoxButtons.OK, MessageBoxIcon.Information)
           Call loadrec()
       Catch ex As Exception
           Trans.Rollback()
           MessageBox.Show(ex.Message, "", MessageBoxButtons.OK, MessageBoxIcon.Error)
       End Try

   End Sub

Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click

       'DELETE record
       Try
           Connect()

           Trans = conn.BeginTransaction

           sql = "DELETE FROM tblsample WHERE ID = @ID"

           cmd = New OleDbCommand(sql, conn, Trans)

           cmd.Parameters.Add(New OleDbParameter("@ID", OleDbType.Integer)).Value = DataGridView1.SelectedCells(0).Value

           cmd.ExecuteNonQuery()

           Trans.Commit()

           conn.Close()
           conn.Dispose()
           cmd.Dispose()

           Call loadrec()

           MessageBox.Show("DELETED!", "", MessageBoxButtons.OK, MessageBoxIcon.Information)

       Catch ex As OleDb.OleDbException
           Trans.Rollback()
           MessageBox.Show(ex.Message, "DATABASE ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error)
       Catch ex As Exception
           Trans.Rollback()
           MessageBox.Show(ex.Message)
       End Try

   End Sub

Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click

       'UPDATE record
       Try
           Connect()

           Trans = conn.BeginTransaction

           sql = "UPDATE tblsample SET sname = @sname,contact = @contact WHERE contact = @ID"

           cmd = New OleDbCommand(sql, conn, Trans)

           cmd.Parameters.Add(New OleDbParameter("@sname", OleDbType.VarChar, 255)).Value = TextBox1.Text
           cmd.Parameters.Add(New OleDbParameter("@contact", OleDbType.VarChar, 255)).Value = TextBox2.Text
           cmd.Parameters.Add(New OleDbParameter("@ID", OleDbType.Integer)).Value = DataGridView1.SelectedCells(0).Value

           cmd.ExecuteNonQuery()

           Trans.Commit()

           conn.Close()
           conn.Dispose()
           cmd.Dispose()
           Call loadrec()
           MessageBox.Show("UPDATED!", "", MessageBoxButtons.OK, MessageBoxIcon.Information)

       Catch ex As Exception
           Trans.Rollback()
           MessageBox.Show(ex.Message)
       End Try

   End Sub