Private Sub UserForm_Initialize()
Dim Codes As New Collection
Dim Rng As Range
Dim c As Range
Dim i As Long
Dim j As Long
Dim Temp As Variant
With Worksheets("AL Zones")
Set Rng = .Range("A1:A" & .Range("A65536").End(xlUp).Row)
On Error Resume Next
For Each c In Rng
Codes.Add c.Value, CStr(c.Value)
Next c
On Error GoTo 0
End With
With Worksheets("FL Zones")
Set Rng = .Range("A1:A" & .Range("A65536").End(xlUp).Row)
On Error Resume Next
For Each c In Rng
Codes.Add c.Value, CStr(c.Value)
Next c
On Error GoTo 0
End With
With Worksheets("GA Zones")
Set Rng = .Range("A1:A" & .Range("A65536").End(xlUp).Row)
On Error Resume Next
For Each c In Rng
Codes.Add c.Value, CStr(c.Value)
Next c
On Error GoTo 0
End With
If Codes.Count > 1 Then
For i = 1 To Codes.Count - 1
For j = i + 1 To Codes.Count
If Codes(i) > Codes(j) Then
Temp = Codes(j)
Codes.Remove (j)
Codes.Add Temp, CStr(Temp), i
End If
Next j
Next i
End If
For i = 1 To Codes.Count
ComboBox1.AddItem Codes(i)
Next i
End Sub