The combobox only handles a single column of displayed data. It has a displaymember and a valuemember property for binding to the datasource. But if you must display multicolumn in a combobox then you can concatenante your column values, like Eddy's shown in SQL. In VB this works like:
Dim FnLn As String
Dim drRow As DataRow
For Each drRow In DataSet.Rows 'or DataSet.Tables("Table1").Rows
FnLn = drRow("Lastname") & " , " & drRow("Firstname")
cb1.Items.Add(FnLn)
Next
