A method for developing, selling and delivering software applications for real estate multiple listing services, brokers, agents, companies, franchises, and consumers. Stimulation of such nerve is provided via stimulating drugs andor electrical stimulation as a therapy for erectile dysfunction. The present disclosure achieves an IP positioning precision on a street level and has advantageous of simple arrangement and fast response speed. However, if the event datagram is lost, the client transmits every checksum of the leaf nodes in its tree data structure in one request datagram to the web server, and performs data synchronization by receiving changed data from the web server.