If you want to reset all interval jobs when a browser tab is inactive, the best way would be to use clearInterval on window blur. But unfortunately Chrome fires window focus and window blur two times. Here is an embryo to a solution: var M = window.M || {}; M.counter = 0; M.focused = true; M.tick = function() { if (M.focused) { console.log("tic tac " + ++M.counter); } }; M.start = function(e) { console.

To show a popup, we just have to invoke “window.open”, and provide some options to prevent opening this in a new tab: var wnd = window.open('', '\_blank', 'width=750, height=400, location=no, resizable=1, menubar=0, scrollbars=0'); wnd.document.write(''); wnd.document.close(); wnd.document.close(); wnd.focus(); To communicate between parent and child we can refer to parent as window.opener. We can even invoke a function from parent window. Let’s create the most useful function: foo = function() { console.log("foo"); } ```Then just click on "hej" in the popup, and see the console.