>i need to delete the .dll from my folder(test) as ...
>

>IF m.aa >=ctod('11/04/2007')
>
>delete,remove or drop all.dll
>CLEAR events
>quit
>else
>do....
>
>endif
>

ERASE filename.ext

Notes:
Don't use CTOD() for dates anymore. It has ambiguity problems. Your example may mean 11 April or also November 4 depending on settings.
Use other date notations such as DATE(2007,4,11) for example.

Your CLEAR EVENTS positioning looks strange. Normally you would put it in an Exit option in a menu or maybe an Exit button on a Form. To CLEAR EVENTS on a program condition is not good form. Following CLEAR EVENTS you should clean up your environment. Your immediate QUIT may or may not work depending on dangling references.
See:
http://fox.wikis.com/wc.dll?Wiki~AppShutDown
http://fox.wikis.com/wc.dll?Wiki~ManualGarbageCollection
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_foxhelp9/html/9ab3af21-8cd6-4a18-b40b-f789b802aef7.asp?frame=true