Trulia is a great resource, but you do need to do a couple of thingsL
1. I assume that you have a Realtor under contract. Ask your Realtor, if he does not know, ask their Broker.
2. If you are selling without professional representation, then contact an attorney who is experienced with Real estate matters.
In most cases if a seller cancels escrow there will be damages to pay. Put yourself in the shoes of the buyer. What would you expect?