Executing several SQL INSERT statement in ASP.NET VB.NET

Hello!

By pressing a button on the my page, I am executing several SQL Insert statement to save data from my unbounded form to SQL Database. The data is fed from a date control and several combo boxes feed by SQL server. I am very new to ASP.NET and I am sure my code is not optimal at all. So here are my questions and problems:

1. Is there a better way to execute several Inserts (In this example I have included only two but I will have about 15 at the end)?
2. Regardless what I select from the combo-boxes. Only the top record from each combo box is selected and saved to SQL - A quick search I think this has to do with PostBack. But I have no idea ho to fix it and where.

Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Public Class MeetingScheduler
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

    Protected Sub SaveSchedule_Click(sender As Object, e As EventArgs) Handles SaveSchedule.Click

        Dim constring As String = ConfigurationManager.ConnectionStrings("DefaultConnection").ConnectionString
            Dim con As New SqlConnection(constring)
            Dim cmd As New System.Data.SqlClient.SqlCommand
            cmd.CommandType = System.Data.CommandType.Text

            If Me.MeetingDate.Text = "" Then
                MsgBox("Please select the date and try again", vbExclamation, "Attention!")
                Me.MeetingDate.Focus()
                Exit Sub
            End If

        If Not String.IsNullOrEmpty(Me.ComboBox1.Text) Then
                cmd.CommandText = "INSERT INTO MEETINGSCHEDULE (MeetingDate, MeetingID, Assignment, PersonName, Sort) VALUES ('" & MeetingDate.Text.ToString & "', 5 , 'Chairman', '" & ComboBox1.Text & "', 2)"
                cmd.Connection = con
                con.Open()
                cmd.ExecuteNonQuery()
                con.Close()
            End If

        If Not String.IsNullOrEmpty(Me.ComboBox2.Text) Then
                cmd.CommandText = "INSERT INTO MEETINGSCHEDULE (MeetingDate, MeetingID, Assignment, PersonName, Sort) VALUES ('" & MeetingDate.Text.ToString & "', 2 , 'Presenter', '" & ComboBox2.Text & "', 5)"
                cmd.Connection = con
                con.Open()
                cmd.ExecuteNonQuery()
                con.Close()
            End If