To check some conditions you would use IF.

if startdate > enddate then
  messagebox("whatever...)
ELSE
  * Do something
endif

>I think I'm close, I need to do a check before continue on to next step, if I use a Do while I get into a loop I can't get out of and if I use IF it continues on.
>
>I have a start date that needs to greater than the end date so here are the ways of written:
> Thanks
>

>if startdate > enddate then
> messagebox("whatever...)
>endif
>
>do while startdate > enddate
> messagebox("whatever...)
> loop
> exit
>enddo
>