[SOLVED] How to reset Dell monitor resolution

[Sophier_30]

I have a new Mac hooked to Dell Monitor. I was playing with the resolution. I set a wrong value. before waiting any time, the monitor displays out of range and is locked. what do I need to do to reset the resolution?

 

[JackNaylorPE]

Use the manual to bring up the on screen display ...on the U2410, ya hold ya finger spot above the blue ON / OFF LED