checked dataitem of datagridview in textbox

[sidyusuf]

hi frnds,
i m populating a datagridview with two columns i.e checkbox and papername.I m trying to show papercodes(not present in grid but in database ,in the same table where papernames are)in a single textbox with a comma seperator, when i checked papernames accordingly.
this is my used code.

Dim checkCol As DataGridViewCheckBoxColumn = New DataGridViewCheckBoxColumn()
        checkCol.HeaderText = "Select"
        DGVPapers.Columns.Add(checkCol)
Dim ds As New DataSet
        Dim da = New OleDbDataAdapter("select papername from paperset ", con)
        da.fill(ds)
        DGVPapers.DataSource = ds.Tables(0)