As Grids are emerging as the next-generation computing platform, the need for Web-based portals that hide low level details of accessing Grid services for deployment and execution management of applications is increasing. We have responded to this requirement by developing an easy to use, lightweight, scalable, web portal called G-Monitor that allows the user to monitor, control, and steer execution of application jobs on Global Grids. Unlike related systems, the users of G-monitor delegate the responsibility of selection of appropriate resources for execution of their application jobs to the broker.