Camera Flash Types Transcend 1gb High Speed 80x Compactflash Card I Need Plans To Build A Simple, Cheap Device That Will Sense A Camera's Flash, And Trigger Another Flash.?

I need plans to build a simple, cheap device that will sense a camera's flash, and trigger another flash.? - camera flash types transcend 1gb high speed 80x compactflash card

I have a digital camera very well, but I like the lightning. I have also assembled a very good 35-mm camera on the flash type. I know I can by lightning at a distance, but they are too expensive. I prefer some basic plans for the construction of the mine.