Combo/List Box populated by user form entries

I am just getting started in VBA and I have a pretty good start to what I am trying to do. I am basically building a program that will use Excel as the database and report garnering. I have 2 different user forms in the VBA, the first NewWorkOrder and the second WorkOrderDesc. I want to automatically populate the combo box (or list box) in WorkOrderDesc based upon the facility WO Type that was selected in NewWorkOrder. I have the WOType separated on 4 different worksheets, for example, if the user selected "Vehicle" as the WO Type and Facility 10, then I want the combo box (or list box) to populate all instances of facility 10 under the "Vehicle" Worksheet. I have a variable named strFacility and WOType to hold the string values of the selection and NewWorkOrder is hidden so the memory of the strings is still available.

NewWorkOrder form:

[VBA]Private Sub CommandButton1_Click()

'Pass values from NewWorkOrder form to frmVehicle and WorkOrderDesc
strFacility = FacListBox.Value
WOType = WOTypeListBox.Value

'Determine if the Work Order Type is Vehicle and needs the Vehicle Form
'No Vehicle Type selection is needed at this time, so I am commenting this portion out. 9/9/11
'If WOType = "Vehicles" Then
'frmVehicle.Show

'If it is not Vehicles, then proceed to Work Order Desc
'Else:

WorkOrderDesc.Show

'End If

Me.Hide

End Sub

Private Sub CommandButton2_Click()

'Ask for confirmation to confirm user wants to close workbook
Select Case MsgBox( _
"Are you sure that you want to close the Work Order System?", _
vbYesNo + vbQuestion, _
"Confirm Exit.")

Case vbYes
'Close Work Order Workbook if user Cancels work order
'Don't save changes since no WO was entered.
ThisWorkbook.Close SaveChanges:=False


Case vbNo
'Don't Close Work Order System, return to previous screen
NewWorkOrder.UndoAction

End Select
End Sub

Private Sub UserForm_Initialize()

'Populate the Facility List based upon the Database
Dim LastRow As Long, facility As Range
With Worksheets("FacilitiesDB")

'Find the Last Row in the Worksheet
LastRow = .Cells(Rows.Count, 1).End(xlUp).Row

For Each facility In .Range("A2:A" & LastRow)
If Len(facility) > 0 Then FacListBox.AddItem facility.Value
Next facility
End With

'Populate the Work Order Type List - hard coded!
With WOTypeListBox
.AddItem "Vehicles"
.AddItem "Building"
.AddItem "Grounds"
.AddItem "Equipment"
.AddItem "Other"
End With

End Sub[/VBA]

Post the workbook.

Here's the workbook. I have put some data in the worksheets but eventually I want to get to the point that the VBA forms and macros will automatically populate this data.

WorkOrderDesc form initialize errors for me.

Yes, the WorkOrderDesc is not functional right now. I have no clue how to populate this list and the code inside this form is just me trying various tactics. Again, I am new to VBA and programming, so I just figure to take the logical steps through the program that I am trying to create, so when I get to the WorkOrderDesc, my first focus is to get the list box to populate, as well as the combo box below it, but I know if I can understand how to do the conditional populating on one, I could handle the other too.