Hello, >i wrote a program by vfp5. some users will call the program more than once because they click the icon many times. i don't know why they always do that, btw, pls. tell me the command to avoid the duplicate program call. Take a look to UT KB, you'll find a lot info about preventing application from second time start... Speaking generally, you can use several techniques to do that... At least, three different.... >sunny