Sample files of this tutorial, including the *.cpp file, the *.html file, the related *.css files and *.js file, are available for download
If you'd like to learn more about HTML dialog, please see this page for a nice collection of often useful examples.
In Origin, the newHTML X-Function is provided to create a simple HTML dialog easily and quickly. The HTML file and CPP file created by this X-Function are like the templates, you can redesign your HTML dialog based on these two files. Once you go through all tutorials and have the basics about HTML dialog, you can use the newHTML X-Function to construct starter HTML dialog. In Code Builder interface, you can easily select menu Tools:New HTML Dialog... to launch this X-Function.