What is the technical standard name for the USB connector used for Samsung Behold phone
It's a proprietary Samsung connector. Referred to as the Samsung 20-Pin Connector, or S20-Pin connector. It is used for multiple connections, including Audio, Headsets, USB, Serial and Charging.

See http://pinoutsguide.com/CellularPhones-P-W/samsung_d800_pinout.shtml for pinout.