VB.NET อยากให้มันแสดงห้องที่มีสถานะว่างครับทำไงครับ งง ขอบคุณมากครับ

Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Collections
Imports System.Data
Partial Class CheckRoom
    Inherits System.Web.UI.Page
    Private Connect As New Connect()
    Private sql As String
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        sql = "select * from event_tb"
    End Sub
    Private Function check_event() As ArrayList
        Dim room_name As New DataTable()
        Connect.[Select]("SELECT * FROM room_tb", room_name)
        Dim room As Integer = room_name.Rows.Count
        Dim list As New ArrayList()
        Dim i As Integer
        Dim start_date As DateTime = DateTime.Parse(txt_start.Text)
        Dim ent_date As DateTime = DateTime.Parse(txt_end.Text)

        For i = 0 To room - 1
            'sql = "SELECT * FROM event_tb WHERE (start_date BETWEEN '" + start_date.ToString("yyyy/MM/dd") + "' AND '" + ent_date.ToString("yyyy/MM/dd") + "') OR (end_date BETWEEN '" + start_date.ToString("yyyy/MM/dd") + "' AND '" + ent_date.ToString("yyyy/MM/dd") + "') AND room_id ='" + i.ToString() + "'";
            sql = "SELECT * FROM event_tb WHERE (start_date BETWEEN '" & start_date.ToString("yyyy/MM/dd") & "' AND '" & ent_date.ToString("yyyy/MM/dd") & "') AND room_id ='" & Convert.ToString(room_name.Rows(i)("room_id")) & "'"

            If Connect.[Select](sql).Rows.Count > 0 Then
                list.Add(New roomCheck("ห้อง " & Convert.ToString(room_name.Rows(i)("room_name")), "ไม่ว่าง"))
            Else
                list.Add(New roomCheck("ห้อง " & Convert.ToString(room_name.Rows(i)("room_name")), "ว่าง"))
            End If
        Next
        Return list
    End Function

    Public Class roomCheck
        Private m_room_name As String
        Private m_room_status As String

        Public Sub New(ByVal room_name__1 As String, ByVal room_status__2 As String)
            Room_name = room_name__1
            Room_status = room_status__2
        End Sub

        Public Property Room_name() As String
            Get
                Return m_room_name
            End Get
            Set(ByVal value As String)
                m_room_name = value
            End Set
        End Property

        Public Property Room_status() As String
            Get
                Return m_room_status
            End Get
            Set(ByVal value As String)
                m_room_status = value
            End Set
        End Property
    End Class

    Protected Sub btn_check_Click(ByVal sender As Object, ByVal e As EventArgs)
        g_check.DataSource = Nothing
        Dim list As ArrayList = check_event()
        g_check.DataSource = list
        g_check.DataBind()
    End Sub
End Class