Fill in the blank (box)

[adnakarivach]

I am trying to acomplish the following but only got the first parts right:
1.macro to determine the "out" time DONE
2.msge with total DONE
3.box to ask if "anything else" NEED
4.if yes module1.addcopy NEED
5.if no exit sub NEED

Sub OUT01()
If Range("f4") > 0 Then
MsgBox "Can't change!", vbCritical, "Stop"
Exit Sub
If Range("c4") = "" Then
MsgBox "Missing In time!", vbCritical, "Stop"
Exit Sub
Else
Range("d4").Select
Selection = time
End If
End If
BOX GOES HERE
End Sub


Any help will be greatly apreciated... Thanks!
PS> there was a link for a tutorial on boxes posted here a long time ago, I can't findt; does anyone have it?