Publishing Engine Programmer's Guide > The Arbortext Publishing Engine Sub-Process > Writing Arbortext PE Applications in JavaScript > Testing JavaScript Syntax in Arbortext Publishing Engine Interactive
  
Testing JavaScript Syntax in Arbortext Publishing Engine Interactive
You can launch Arbortext Publishing Engine Interactive to test the syntax of the code in your custom JavaScript applications. When you source your JavaScript file, be aware that Arbortext Publishing Engine Interactive will not actually run the application.
To test JavaScript applications using Arbortext Publishing Engine Interactive
1. Your JavaScript file should be in the PE_HOME\custom\init directory.
2. Launch Arbortext Publishing Engine Interactive by choosing it from its shortcut on your Arbortext Publishing Engine program group.
Any scripts in PE_HOME\custom\init are automatically sourced at startup. If the JavaScript application contains syntax or other errors, you'll automatically receive a message explaining the nature of the error.
3. If you wish to leave Arbortext Publishing Engine Interactive running, you can make a change to the JavaScript file and source it manually using the Arbortext Publishing Engine Interactive command line prompt. You would use the source command and specify the path, like the following example:
source path-and-script-name.js
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If the command line is not enabled at the bottom of the interface, choose Options > Preferences. If you want to change the default setting, select the Preferences button. If you want to change the setting for the current session only, select the Current Settings button. Then, on the Window tab, select the Command Line option. You can exit by choosing the save option of your choice.