What happens when an Auto dealer doesn't sign the contract but I did?

I have all of my paperwork and the page of actual sale agreement is BLANK.....completely blank. It doesn't even have info on the vehicle or any date or signature. Not one piece of paperwork, with the exception of the Odometer reading, is signed by the dealership and or has a date of signing. What should I do? Is this legal for them to do? Also, there is a page that must be notarized and it never was...Is my contract valid?