The APGEMS main menu is provided at the top of the APGEMS display.  The main menu is used to set the date and time of the beginning of the release, the release duration, he simulation duration, and the location of the release before running the model.  Additional information can be set using the Options menu. When all parameters are set to the use's satisfaction, the Run button is clicked and the model simulation will begin. A several hour simulation usually takes a few seconds to run on a standard PC. Once the simulation is completed, the model will automatically generate and display initial output graphics.