My Browser won't interpret "ΧΨ" when I load the website I'm building

I pretty much built this website in firebug, then when I copied the code into a text document and tried loading it, firefox wouldn't interpret the "ΧΨ" in the source. However, 开发者_如何学Cit does a fantastic job using them while I'm typing this.

Wassup wid dat?

You can't just type a character into an HTML tag, it must be a valid character and if not use the proper character code. See this list: http://htmlhelp.com/reference/html40/entities/symbols.html

You can use Entity, Decimal, or Hex to represent your character like this:

<p>&Chi;&Psi;</p>

That's the HTML representation of "ΧΨ"

Cheers