>> What I don't know how to do is poupulate the 2 column. The listbox is being populated base on the user input from a textbox. <<

Depends on the RowSourceType. This sounds to me like an ideal RowSorceType would be 6-Fields and that the RowSource should come from some sort of parameterized view. So, if you have the view (let's suppose it is called lv_Combo) set up as a parameterized view with the view parameter called vp_Value, set up the combo like this

RowSourceType = 6-Fields
RowSource = lv_Combo.Description, iPK
BoundTo = .T.

Then, this code called from the command button's click()

vp_Value = This.Parent.txtWhatever.Value
REQUERY( 'lv_Combo' )
This.Requery()

HTH