VB.Net DataBind

I am pretty new of VB.Net. I have a question here.
See the code below.
The fronted is a table, and the code behind is doing the data bind. All I need is add 2 more filed to the frontend and bind these 2 fields to database (I already know the 2 new data if from differnet database, i need to link the 2 tables)

But now my problem is I dont know how to find out which table (data source) those fields are bind to?
Dim DI As New DT_DealInformation(Session("pno").ToString.Trim)
DT-DealInformation must be a pre defined class which may contain the database information?
But I dont even know how to locate the place of DT_dealinformation.
I did rearch in entir project but does not show.
Need some advise .
Thanks.

#Region "Bind CTI Space Information"

        Private Sub BindCTISpaceInformation()

            Dim DI As New DT_DealInformation(Session("pno").ToString.Trim)
            Dim dr As SqlDataReader
            dr = DI.GetCTISpaceData((Session("Pno")), (Session("LeaseId")), (Session("Space_Number")))
       

            While dr.Read

                If IsDBNull(dr("RegionCode")) = False Then
                    Me.txtRegion.Text = dr("RegionCode").ToString
                Else
                    txtRegion.Text = ""
                End If

Select allOpen in new window