Embedding Unity to a web page

I tried to embed Unity into a web page in order to know how to do it when I have the actual Unity project finished. It wasn't seamless; the Unity file itself needs to be a .unity3d file rather than a .unity file. Any files I've created in Unity so far have been .unity files so I need to figure out how to save my file with that extension. It may be a simple problem but I haven't done enough research yet on it to know. Here is the screenshot:

I got the code from the Unity community and added it to my own. Here is a screen shot of the code: