There isn't a contract until after an offer has been accepted, or in the case of a short sale an approval by the lender(s) and the earnest money deposit has been given by the buyer. In a short sale, an approval by the lender(s) can take as long as a year. So, it is wise to make offers on every home that interest you and then accept the one that you like and cancel the rest.
I am an agent, but I am a homeowner first. I have purchased homes in California, Hawaii, and Portugal. Let's talk Real Estate. Let me know if I can be of any help.