Adding row to gridview always replacing current row

Good day,
I am using 2 gridview in asp.net, one getting results from an AD Lookup Powershell and on selected index change I basically grab the cell value and insert a row in the second gridview. 
My issue is that when I insert a row in my second gridview instead of adding it to the gridview it replace the record that is currently there. 
Here is my code to add: 
Protected Sub SearchResultsGridView_SelectedIndexChanged(sender As Object, e As EventArgs) Handles SearchResultsGridView.SelectedIndexChanged Dim row As GridViewRow = SearchResultsGridView.SelectedRow Dim strDisplayName As String = row.Cells(0).Text.ToString() UsersToAddGridView.Visible = True If ViewState("CurrentTable") IsNot Nothing Then Dim dt As DataTable = DirectCast(ViewState("CurrentTable"), DataTable) Dim dr As DataRow = Nothing If dt.Rows.Count &g ...