Doubleclick causes multiple start of my application

When I Doubleclick on a file my application starts as it should be. But if i doubleclick another file my application starts a second time ... ??
how can i avoid this ??
I would be very glad to get some ideas of u.
Thanks a lot,
Marko

[olivier]

Maybe you should look at the code of Pview.

When your application starts you look if the process already exists. If yes, your application exits.

[Benoît SAENE]

Yo may read Microsoft Knowledge Base, Article ID Q109175 (16 bits) and Q141752 (32 bits). You will find an example showing how to enable only one instance of your application at a time.
In fact, you have to change InitApplication(), InitInstance() and ExitInstance() of your App Class to register your application and then verify if your application isn't already registered.

Thanks a lot for your posting, they got me very close to the solution of my problem !!
Now my application starts only one time but how do I let my program know, that it has to load new data, if i double clicked on a file in the explorer ??
Do u have any idea ?
Marko