sb.append("<H1>Hangup</H1>");

...

Hangup

Hangs up the call.<br>");        sb.append(

                "You don't normally need to use Hangup as in normal circumstnaces circumstances the call will naturally come down when either end hangs up.<br>");

        sb.append("You might use hangup if you want to force a call down because no one is available to take a call.");