The anticipated increase in popular use of the Internet has created more opportunity in information dissemination, E-commerce, and multimedia communication. It has also created more challenges in organizing information and facilitating its efficient retrieval. From the network perspective, there are additional challenges and problems in meeting bandwidth requirement, as also in network management. In response to this, new techniques, languages and paradigms have evolved which facilitate the creation of such applications. Certainly the most promising among the new paradigms is the use of mobile agents. In this paper, mobile agent and client-server technologies are applied in an E-commerce application and a comparative study is discussed. We report an implementation of a banking system, whose database may be distributed at different sites on the Internet. A customer can send his/her mobile agent to perform various tasks involved in banking and get back an appropriate result or can use client-server methodology to perform the same task. PMADE is used as the platform to develop these mobile agents. Security checks have been also implemented, as this is an important requirement in E-commerce.