Well, you can do one of three things that I can think of. One is to use the Insert Symbol function if you have it. That’s where you get other special characters such as em dashes and curly quotes. So try that first. I think Dreamweaver has that. Another is that you can create a little graphic, either by making the arrowheads yourself (you need four positions, right?—four arrowheads?) or by bringing them in from software that has all the flowcharting symbols, such as PowerPoint. And finally—reaching a little here because I’ve never tried this—you might look up the ASCII characters for the four arrowheads and try invoking them directly in HTML. If I were doing it myself, I would create the flowchart in more congenial software and put the whole thing into my web page as a graphic.