Trying To Prepare For Every Possible Input Box Response

I have an input box that should only have numeric input. I have arranged for it to start loop back to the beginning of the box if someone enters letters instead of number, simply hits enter instead of making an entry, exiting on cancel. Now I need to have it loop if someone hits the space bar one time or more. Here is what I have:

Delta:    On Error GoTo ErrHandler1    Response = Application.InputBox(Prompt:=MyPrompt, Default:=MyPrompt2, _    Title:=MyTitle)    If Response = 0 Then GoTo Delta    Z = Response    If Response = Cancel Then    MsgBox ("You have chosen to exit the macro. Shutting down.")    Exit Sub    End If    If Response = False Then GoTo Delta    If Response = 0 Then GoTo Delta