Inserting Name From Listbox Into Query

I have a listbox inside a subform. I want to use the 'click' Event on a "search" command button (found on the main form) to trigger
a query from inside that listbox and fill it with values from a table. The following is the argument I have written for that event procedure:


Private Sub CommandSearch_Click()
Me.GS_SearchSF.Form.listSF1.RowSource = _
"SELECT MaxSize1 " & _
"FROM GS_Ctg_Float " & _
"WHERE Supplier = '" & Me.GS_SearchSF.Form.SupplierQuery.Value & "';" 'THIS ONE ISN'T WORKING
End Sub


Except as you might imagine, it is not working. It works when I just type a name from that table into the argument in place of
the text seen above in red. For instance:

Private Sub CommandSearch_Click()
Me.GS_SearchSF.Form.listSF1.RowSource = _
"SELECT MaxSize1 " & _
"FROM GS_Ctg_Float " & _
"WHERE Supplier = 'Viracon';" 'THIS ONE WORKS
End Sub

What am i doing wrong?

Here's some background:

GS_SearchSF is the name of my subform

listSF1 is the name of the list box in the SubForm that the
query is supposed to fill

SupplierQuery is the name of the list box in the subform
I want to extract the value from and put into the query