It's a short plant and reaches a max. of 10-12 inches.
SOLVED: Is this a type of Zinnia?
Well, the leaves look like it. It's either that or maybe a plant called Creeping Zinnia whose latin name is Sanvitalia ~ the leaves look like the ones in your picture and the blooms are yellow, but the centers are darker, I think.
Dinu: It is Melampodium [Leucanthemum Paludosum] It is an annual. I use it where you would plant Marigolds. Also very good in containers. It blooms all summer.
You beat me to it, lol. I finally found one I know what it is!! It reseeds really good and the mildew doesn't affect it as badly as it does zinnias.
Thanks very much Debby. It is indeed what you said. I also saw your entry in the P-database.