If you don't have the contents of an existing Web application to use to test debugging, locate Session_VBScript.asp. This file is part of the standard IIS 5.0 installation on Windows 2000, and you can find it in the \inetpub\iissamples\sdk\asp\applications directory. Drag the file to the newly created directory. Session_VBScript.asp is a standalone Active Server Pages (ASP) file that serves as a great test for debugging.
You now have a Visual InterDev environment ready for debugging. Let's put it into action.
Putting IIS Debugging into Action
When you open the Visual InterDev project you just created, you can add the files and folders of the Web application to your Visual InterDev project. To add your folders, right-click the project name, then select New Folder. To add your files (or .asp files such as Session_VBScript.asp), right-click the project name, then select Add, Items. Next, locate the start file for your Web application (e.g., default.asp or default.htm). From Visual InterDev, right-click the start file and click Set As Start Page.
Now, choose an .asp file in your Web application that you want to debug. Edit the .asp file by opening it within your Visual InterDev project. Select a location in which you want the debugger to break—in other words, stop your .asp file in the middle of its operation to examine the values of any variable it might be using. To stop the .asp file, enter the reserved word STOP within a section of server-side ASP code. You can quickly identify the server-side code within an .asp file by the delimiters <% and %>, which Visual InterDev highlights in yellow. Save the file.
Press the F5 key (or choose Debug, Start from the Visual InterDev menu), and you're off and running. The message that Figure 7 shows will appear. Click Yes. (This message appears only once.) Then, the Debugging: Name and Password Required dialog box appears, which tells you that you've succeeded in setting up ASP debugging on this project.
After you authenticate, you can examine the values of variables that are being used in the Web application. Notice that your browser is in a suspended state, waiting for Visual InterDev to act. The real power of this kind of debugging is that it lets developers see the values of many of the variables. In this way, they can find out whether a DLL they're using is passing them the kind of values they expected, and if not, debugging can help them figure out what's needed. Visual InterDev debugging also allows a closer look at the routines' step-by-step processes, which is a tremendous help in weeding out the bugs in code under development.
For example, from Visual InterDev, choose View, Debug Windows, Immediate. In the Immediate dialog box, type the name of a variable that the .asp file you're debugging is using preceded by the print statement for VBScript, which is a question mark (?), such as
"? Session("SessionCountVB")")
Visual InterDev outputs the value of the variable to the immediate window, as Figure 8 shows.
Debugging Makes Development Easier
Although setting up Visual InterDev for debugging is a lengthy process, the increased environmental control that this kind of debugging affords software developers is well worth the effort. For more information about configuring IIS debugging in Visual InterDev, go to http://msdn.microsoft.com/vinterdev/technical/articles/debugging.asp. Next month, I'll show you how to set up, configure, and use the Win2K Indexing Service on the Internet and on your corporate LAN, intranet, and extranet.
Note: If your instructions include a step to clear the FrontPage Server Extensions check box, ignore them. Earlier versions of the Help documentation erroneously include this step.
Note: You don't actually need to add STOP statements within your .asp files. Because debugging is working correctly, you can simply set breakpoints by choosing the line on which you want to break and selecting Debug, Insert Breakpoint from the Visual InterDev menu. You can also click in the left margin of your ASP editing page, which inserts a breakpoint and leaves a large black dot in the margin. Click the black dot to remove the breakpoint.