Firefox JS Breakpoint Example

What to do?
  1. Open the Firefox Developer Tools.
  2. Select the Debugger tab in Dev Tools
  3. Select the breakpoints.html from the file list.
  4. Try to place Javascript breakpoints in each of the script tags.
  5. Observe that breakpoints can be set in any script tag with a message stating breakpoints work.
  6. Observe that you cannot set a breakpoint in the one script tag with the embedded HTML comment for antiquated user agents that don't support the script tag.