jQuery - slide div into screen

		var showingSlider = false;

		function show_hide_div_on_scroll_jquery() {
			if ($(window).scrollTop()>300)
		     {
				 if (!showingSlider){
		             showingSlider=true;
		             $('#header-hidden').animate({
						 top: 0,
						 opacity: 1,
					 }, 500);
		         }
		     }
		    else
		     {
				 if (showingSlider){
		             showingSlider=false;
		             $('#header-hidden').animate({
						 top: -150,
						 opacity: 0,
					 }, 500);
		         }
		     }
		}
		show_hide_div_on_scroll_jquery();

		
		// https://tutorialdeep.com/knowhow/show-hide-div-on-scroll-jquery/
		// https://stackoverflow.com/a/26171569
		$(window).scroll(function() {
		   show_hide_div_on_scroll_jquery();
		});