Javascript: Debugger

Although I already quite spent times at coding Javascript, I just knew this useful feature in Javascript, that we can put debugger keyword at new line of the code (without any semi colon) that will function like breakpoint. If your browser has already set to enable debugging (Tools > Internet Options > Advanced > Uncheck Disabled Script Debugging, then when the browser execute that line, it will prompt you want to debug the script using any debugging tools (VS2003/2005, etc).