jQuery / JavaScript enhancements on WordPress website

Hello, we need following things to adjust on this website: [login to view URL] It should be done this week. 1. Intro screen input validation: [login to view URL] We have a simple input on the homepage that should accept just numbers within a certain interval which are years from around 1920 to 2009. It should be checked each time user types something (either on numpad, top keys, inline keyboard or any other way) so the first character can be just 1 or 2, second 9 or 0 and then any number. Validation should be done on each key press and user should be notified by some simple tooltip error. The field does not have to be an input, it just needs to pass a year to a second step (for example [login to view URL]). 2. Intro screen input animation: [login to view URL] We would like to display an animated random numbers within an interval (1920 - 2009) until user focus /clocks on input field. The animation should simply switch / type numbers by random. Something like [login to view URL] ([login to view URL]) just with valid years. 3. Table address with History API: We are having a generations table below the static content on a second page [login to view URL] We need to change the URL of the page to [login to view URL] once user scrolls to the table (or clicks the button). The URL should point to this table even if user opens this directly with a link but this page will be prepared separately on WordPress side, the history API should only assing this URL. 4. Disable scroll: This point is associated with point 3. We need to disable the scroll to the top of the page once we change the URL to [login to view URL] So once user scrolls to the table area, he won’t be able to scroll back to the original top of the page (so basically he stays on [login to view URL] ever since).