1. Basic functionality of the page can be used without mouse, just with keyboard (using TAB button to navigate between the links / buttons). Whenever I TAB, the active/focused item should be clearly indicated e.g. with a border or different background color.
2. You should be extremely careful not to override the native keyboard shortcuts of the browser. E.g. SHIFT+ARROW_LEFT/RIGHT/UP/DOWN are commonly used to expand text selection (TheNextWeb is an offender here, as they treat arrow left/right as a shortcut for "prev/next article" which extremely annoys me). Ctrl+L focuses the location bar of the browser. AltGr+[a-zA-Z] are used in many languages to enter diacritics like "ó".
I've added 'window.onbeforeunload' to test a weird behavior of IE<=8 (actually I could tweak the JS on the page to add the listener only for old IE). When you have a link like '<a href="javascript:void(0);">' + onbeforeunload + click event listener bound to <a> doesn't return false, then clicking (from mouse/kbd) such a link triggers onbeforeunload().
1. Basic functionality of the page can be used without mouse, just with keyboard (using TAB button to navigate between the links / buttons). Whenever I TAB, the active/focused item should be clearly indicated e.g. with a border or different background color.
2. You should be extremely careful not to override the native keyboard shortcuts of the browser. E.g. SHIFT+ARROW_LEFT/RIGHT/UP/DOWN are commonly used to expand text selection (TheNextWeb is an offender here, as they treat arrow left/right as a shortcut for "prev/next article" which extremely annoys me). Ctrl+L focuses the location bar of the browser. AltGr+[a-zA-Z] are used in many languages to enter diacritics like "ó".