I\'m using Firebug 1.5.4. When I reference an undefined variable or some such, it breaks right where the problem occurs, and throws me into the debug view where I can see t
Put a debugger; statement in your code or use the Script tab of firebug to click on a line number (which inserts a breakpoint).
debugger;
Script
If you only want to do it when you throw an exception, you could put the debugger statement in a catch block.
catch