Two Broker Situation

We are looking for an apartment to buy in Manhattan area. We started working with one agent and saw few apartments with her. However, we realized that she is not very much aware of coop buying process in NYC area. So, we found another agent who is more experienced to handle our situation. Can we put an offer through this new agent for the apartments seen with the first agent?? We didn't sign any contract with the first agent. So, is there is any law prohibiting us from going ahead with the new agent for our purchase of apartments seen earlier?? Will the first agent be entitled to any commission by law in this situation??