By Amy E. Feldman

PHILADELPHIA (CBS) - Let’s hope you haven’t just invented a way to make your money disappear.

French electrician Andre Cassagnes, who passed away recently, proves that any schmoe with a great idea can come up with the next big thing, like his invention the Etch a Sketch. And there are hundreds of invention promotion companies out there who count those schmoes like us as their best customer.

For a relatively small fee of a couple of hundred bucks, they will conduct a patent search and market study proving that your invention is destined to be bigger than the Etch a Sketch – and then offer that for a big fee of thousands of dollars, to bring your product to market.

But inventors beware!

The US Patent and Trademark Office (PTO) has a link to published complaints about companies like that who take your big payment and then invent a way to disappear. Before you give any money, go to USPTO.gov to research how to do a patent search yourself for free and then on the website find a certified qualified attorney to help for real.

The last thing you want is for your dream and your money to disappear like a stick figure on an Etch a Sketch.