How to retrieve data from autocomplete textbox

 am working on a stock management system and i added textbox with autocomplete codes..i have two forms one is items form and other is stock in. now i can able to get itemcodeID from stockin itemnumber textbox with autocomplete codes but when i select that item number its not giving me the description..i mean to say that if user search itemcode in stock in form then he should get description and quantity of that item automatically... i am using vb.net and ms sql .

What I have tried:

<pre>Private Sub getData(ByVal dataCollection As AutoCompleteStringCollection)
    Dim connetionString As String = Nothing
    Dim connection As SqlConnection
    Dim command As SqlCommand
    Dim adapter As New SqlDataAdapter()
    Dim ds As New DataSet()



    connetionString = ("Server= DESKTOP-QN6F623; Database = dbo_main;Integrated Security = false;User ID=dis;Password=0m3rP@ss")
    Dim sql As String = "SELECT itemnumber FROM items"
    connection = New SqlConnection(connetionString)
    Try
        connection.Open()
        command = New SqlCommand(sql, connection)
        adapter.SelectCommand = command
        adapter.Fill(ds)
        adapter.Dispose()
        command.Dispose()
        connection.Close()
        For Each row As DataRow In ds.Tables(0).Rows
            dataCollection.Add(row(0).ToString())
        Next
    Catch ex As Exception
        MessageBox.Show("Can not open connection ! ")



    End Try

End Sub

Private Sub stockin_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    Stockin_itemnumberTextBox.AutoCompleteMode = AutoCompleteMode.Suggest
    Stockin_itemnumberTextBox.AutoCompleteSource = AutoCompleteSource.CustomSource
    Dim DataCollection As New AutoCompleteStringCollection()
    getData(DataCollection)
    Stockin_itemnumberTextBox.AutoCompleteCustomSource = DataCollection




End Sub