The main problem is that the disabled attribute is not supported by all browsers.
This code line is using jQuery to select all buttons on a page, and then disable them.
Screen properties in jQuery
There are a few properties that you can use to control how your screen looks in jQuery. The following are all of the properties that you can use to change the way your screen looks:
width: This property sets the width of the screen.
height: This property sets the height of the screen.
orientation: This property sets how your screen is oriented. You can choose portrait or landscape mode.
scrolling: This property controls how your content scrolls onscreen. You can choose to have it scroll automatically, or you can control how much it scrolls at a time.
What is jQuery