I have an invention, what should I do?

[Linda]

I have an invention idea that I want to put into market. I don't want to submit to invention help company. Because in 2006 I had one invention idea. I was looking for that product but there was't in the market. So I contacted, Davison company. The rep called me, interviewed me and let me filled up form about the idea. I submitted everything. Then they required a fee for an evaluation, which I didn't have money that time.
So, I did not pursue it, but a year later I saw the product in Walmart shelf.
This time I have another invention idea, but I want to pursue myself before I submitted to any company.

I need some info....Thanks.