I need help on ubuntu 9.10 crontab GUI application

need to setup cron every 30 min to start and end Adobe AIR application which is not happening at present. I am using following command.

*/30 * * * * /opt/myapp/myapp

can any one tell me what mistake I am making.

What I found was cron does not execute GUI app. Only command lines are accepted jobs are accepted.

Please guide me what needs to be done.

The application doesn't start because it doesn't know which display to connect to.

Typically the display is the first display, number zero, in the system. Add the line DISPLAY=:0 to the crontab, before your schedule line. But note that this will fail if you're not logged on to the system at the time, or if there are multiple users logged on.