(Web front-end development engineer, whose main responsibility is to develop client products using various web technologies such as HTML / CSS / JavaScript / flash. Complete the development of client program (i.e. browser side), develop JavaScript and flash modules, simulate the overall effect in combination with background development technology, carry out web development to enrich the Internet, and strive to improve user experience. This tutorial is supported and proofread by @ fish C subtitle group. Welcome to review and eat!)