Magento's themes and extensions aren't always of the highest quality, and when I ran into an issue on one of my client's Magento sites that the quantity increment and decrement arrows didn't work on the single product page (product/view.phtml) I tossed in the following quick jQuery code to make it...
Include jQuery in the JavaScript Console
To include jQuery in the JavaScript Console in Google Chrome all you have to do is run the following 'single' (not really single but it's put made into a single line) easy to copy and paste line. The line below will include the latest (as of this writing) 3.1.0 jQuery...