การพิมพ์ใน txtbox แล้วให้ไป search ฐานข้อมูลทำอย่างไรครับ

        Dim cls As New MyData
        Dim dv As DataView
        Dim dt As DataTable = cls.GetDataTable("select productid,productname " & _
           " from products order by productname")
        dv = dt.DefaultView
        Dim A1 As New AutoCompleteStringCollection
        For Each drv As DataRowView In dv
            A1.Add(drv("productname"))
        Next
        TextBox1.AutoCompleteMode = AutoCompleteMode.Suggest
        TextBox1.AutoCompleteSource = AutoCompleteSource.CustomSource
        TextBox1.AutoCompleteCustomSource = A1