With the thin client, even though your program executes on the server, the user interface is projected onto the client. You can choose whether the UI displays inside the user's browser window or in a separate application window. How and where your program starts depends on the HTML commands that you use to include it on your Web site. See Updating Your Web Page to Invoke Your COBOL Application for details. Listed below are some things to consider when choosing a windowing method.
In this case, your COBOL program starts inside the user's browser window. Nearly all of the ordinary functions of your COBOL program are available to your user and your program has access to library routines that can be used to communicate with the browser.
In this mode, users also have access to browser functions like Forward, Back, and Search, but when they use these functions, the COBOL program terminates. To avoid losing data, the COBOL program should be designed to handle the closing action gracefully within ten seconds. If users return to the page from which they launched the ACUCOBOL-GT application, it reloads like any Web page.
Note that because of a Microsoft child window restriction, applications running inside a browser window cannot display a main window menu bar as you or your users might expect. To work around this restriction, you can program your application's menu functions to be accessed from a toolbar or a pop-up menu that is activated with the right mouse button.
In this mode, your COBOL program starts in a window separate from the browser, making it look the same as it would if it were launched locally. All the functions of your original program are available to users, including a main window menu bar.
Although your program cannot access the library routines used to communicate with the browser in this mode, users can still access functions like Forward, Back, and Search simply by activating the browser window. However, when the user selects a browser function, the runtime object terminates. This is because the runtime object executes as an object related to the HTML page, even when running in a separate window.