Update information in database

 Private Sub Updatebtn_Click(sender As System.Object, e As System.EventArgs) Handles Updatebtn.Click
        If TextBox1.Text = "" Or TextBox2.Text = "" Or TextBox3.Text = "" Or TextBox4.Text = "" Or TextBox5.Text = "" Or ComboBox1.Text = "" Then
            MsgBox("Please Fill All Details")
            Exit Sub
        End If
        Try
            con.Close()
            con.Open()
            str = "UPDATE Customers set CustomerName=@name,Address=@Address,Phone=@Phone,EyePower=@EP,ConsutantDoctor=@CD where CustomerID=@CID"
            cmd = New OleDbCommand(str, con)
            cmd.Parameters.AddWithValue("@name", TextBox1.Text)
            cmd.Parameters.AddWithValue("@Address", TextBox2.Text)
            cmd.Parameters.AddWithValue("@Phone", TextBox3.Text)
            cmd.Parameters.AddWithValue("@EP", TextBox4.Text)
            cmd.Parameters.AddWithValue("@CD", TextBox5.Text)
            cmd.Parameters.AddWithValue("@CID", ComboBox1.Text)
            cmd.ExecuteNonQuery()

            MsgBox("Record Updated Successfully", MsgBoxStyle.Information, MsgBoxStyle.OkOnly)

        Catch ex As Exception
            MsgBox("Error", ex.Message)

        Finally
            con.Close()
        End Try
    End Sub
End Class