In this video we look at purposely making some errors in a short JavaScript program and looking at the signatures of these errors both in Visual Studio Code and in the (Edge) browser. We see in VS Code how the color coding, squiggly underlining, and inconsistent/unexpected indenting (when we choose to format) can all indicate the possible position of an error. We also show how to open the Console in the browser. We distinguished between syntax errors and run-time errors. We also added code to help us debug using both alert() and console.log() to indicate how far we progressed through some code before it stopped executing due to an error.