I have created a userform to have multiple inputboxes in one Window
Everything works, but I wanna add some specials e.g check if one of the input boxes is empty and IF one of them is empty (for example if someone presses enter) a msgbox will pop up and says sth like “Start input box is empty, fill it out again”
and let the user try again to fill out the inputbox
If they want to cancel, I already set up a cancel button

My code:

Do

If startInput = vbNullString Then
   i = MsgBox("Start fehlt, try again?", vbOKCancel)

    If i = vbOK Then
      * LET THE USER DO ANOTHER INPUT*
    End If

ElseIf EndInput = vbNullString Then
    MsgBox "Ende fehlt"
End If

Loop While startInput = Empty Or EndInput = Empty

how do I tell my code, to start the userform again?