Master each chapter with free interactive exercises online. Live simulation lets you see your practice code run in your browser. 2,000 lines of color-keyed sample code break it all down into easy-to-learn chunks. Extra help through the rough spots so you're less likely to get stuck. Tested on non-coders—including the author's technophobe wife. Become fluent in all the JavaScript fundamentals, in half the time. Display alert messages to the user Gather information through prompts Manipulate variables Build statements Do math Use operators Concatenate text Run routines based on conditions Compare values Work with arrays Run automated routines Display custom elements on the webpage Generate random numbers Manipulate decimals Round numbers Create loops Use functions Find the current date and time Measure time intervals Create a timer Respond to the user's actions Swap images Control colors on the webpage Change any element on the webpage Improvise new HTML markup on the fly Use the webpage DOM structure Insert comments Situate scripts effectively Create and change objects Automate object creation Control the browser's actions Fill the browser window with custom content Check forms for invalid entries Deal with errors Make a more compelling website Increase user-friendliness Keep your user engaged