i would like to know how to limit user of using a shockwave in a period. :'(

Your question is extremly vague and nondescriptive... to the point where no one could possibly have any idea what you're talking about.

Are you reffering to the Shockwave plug-in? And maybe you want to control how frequently a user plays games or watches cartoons or something...

Please elaborate so that we may better assist you.

Sorry, my english not good.

For a shockwave, normally we can download it and use, but just in a short period. After that it will ask us to buy it, if still want to use it. Right?

What i want to know is, for normally how the programmer do to count the period?

:'(

U mean how the software finds out that the trial period is finished & prevents u from using it? Some check ur PC clock & some have different methodes that i'm not aware of

yes amir , i have tried setting my clocks back so many times , even in bios , they are more clever than this now

Thank you very much Amil , yr info is good for me.

If someone know other method, please let me know. Thank you!!

You could maintain an encrypted key in the registry that stores how many days are left until your software expires. But if you're going to have to decrypt it to determine its value, then anyone else may do the same, so it's not fool-proof.

That's the clock-dependent one. Isn't it?

You're right, you'd have to keep checking against the system clock every time the program starts. Having a trial program that ran for only, say, 15 times would seemingly be a better choice.