Acted for plaintiff vendors, unled– estate agents – contract – construction of agent’s authority – entitlement of agent to separate commissions in respect of successive sales of the same property – second sale not covered by the terms of the agent’s written authority – continuing authority expressed to arise if the property is not sold during the exclusive authority period (as defined in REIV retainer) – ss 49 and 50 Estate Agents Act 1980 (Vic).