Cutting Out

Hello,
Does this sound familiar to anyone?! It doesn't matter if I'm online or not, it happens all the time, my monitor keeps cutting out and it's becoming more fequent! It happens every minute or so - it just flashes on and off and then comes back on again. It doesn't disconnect or loose whatever I'm doing. It's a Dell PC running on Windows XP. Any advice/suggestions appreciated!
Thanks.

What is the exact Dell model & # ?

Do you have another monitor and or cable to try?

Also look under Device Manager: Start/Run/ devmgmt.msc | Monitors

Click the (+) then right click your monitor then click Properties

Any errors or yellow exclamation points listed there?

SOunds like a loose cable or possible monitor on the way out - do the leads 'wobble' where they join the PC/Monitor? when they wobble does problem arise? if so tighten cables to PC and Monitor. Apart from that and the advice already provided, how about an old VGA card just in case its that on the blink - just substitute it and see how it goes.