Untitled

Imports System.IO

Public Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim test As String = String.Empty
        If IsPostBack Then
            test = "PostBack"
        Else
            test = "not a post back event"
        End If
    End Sub

    Protected Sub btnDoSomething_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnDoSomething.Click
        Dim output As String = String.Empty
        For Each li As ListItem In CheckBoxList1.Items
            If (li.Selected) Then
                If (output.Trim = String.Empty) Then
                    output = li.Text
                Else
                    output = String.Format("{0} {1}", output, li.Text)
                End If
            End If
        Next
    End Sub
End Class