You've already recieved some good advice about how to include the JavaScript, but there are a few points I'll raise as an aside.

1. The language attribute is deprecated and the type attribute is required. This change happened in HTML 4, which is about a decade old. There is no reason to be using HTML 3.2 these days.
2. Using the navigater.appName to identify the browser is very fragile and should be replaced by object detection.
3. The only thing that attempting to block the context menu will achieve is to annoy users who use the context menu (and note that "preventing users from accessing the context menu" and "preventing users from viewing source code" are not included in the above!). You may find my comments on Protecting images and source code on the web from thieves useful.