to add try catch block u type try and give two tab entry using key board u will get the try catch block automaticly

Luc -- My apologies, on not seeing your first post. Well, that covers my requirement. cheers

All -- I thank everybody for dropping in and letting me know the various aspects. I still couldnt figure out why the trouble is happening. I can successfully watch a folder and get the file changed/created/deleted notifications, but when I try opening a file in UG(Unigraphics CAD App) (The next line in code is opening a file in a CAD Application) it throws out an error "Attempt to read or write protected memory." Hence I am forced to use timer. But timer is not a true solution. Probably I can send in the code and a small file to be opened in CAD, but I am dubious, whether somebody will have the CAD App. Code : C# CAD APP: UG NX 5 Thanks and Cheers Thomas