Add same list in multiple comboboxes

Hi guys
I have written the following code but its giving me runtime error "Object required".

ANy help would be much appreciated.

Private Sub UserForm_Initialize()
loadcombos (ComboBox2)
loadcombos (ComboBox3)
loadcombos (ComboBox4)
loadcombos (ComboBox5)
   
End Sub

Public Sub loadcombos(a As ComboBox)
a.AddItem "Late post"
a.AddItem "High volume"
a.AddItem "Work flow"
a.AddItem "Staffing issue"
a.AddItem "Support elsewhere"
End Sub