Good faith deposit before bank accepts offer?

[Raj Mistry]

Among multiple offers, the listing agent has chosen my offer as the strongest one and is in the process of negotiating with the bank (this is a short sale). However, the listing agent is also insisting that we open escrow now and for me to wire my deposit into escrow. Is this OK considering the bank hasn't officially accepted my offer yet? Thanks in advance for your advice/insight.