var menu,
socialbar,
box,
abstand;

$(document).ready(function() {
// -------------------------------------------------------------------------
// - FIXIERUNG VON MAINNAV UND SLIDER NAV BEIM SCROLLEN
// -------------------------------------------------------------------------

	menu = $("#menu"),
	socialbar = $("#socialbar"),
	box = $("#menu .box"),
	abstand = $("#main-navi").height() + $("#menu .box").height() + 171 + 40;

	$(window).resize(function(){ 
		checkSize();
	});
	
	$(window).scroll(function(){
		checkScrolling();
	});
	
	checkSize();
});


function checkSize(){
	var margintop =  $(window).height() - abstand;		
	if (margintop < 0)
		margintop = 0;	
	box.css('margin-top', margintop);
	
	checkScrolling();
}

function checkScrolling(){
	var scrollTop = $(window).scrollTop();
	
	//SLIDER NAV
	if(scrollTop >= 500 - 118) {
		menu.addClass('menu_fixed');
		socialbar.addClass('menu_fixed');
	} else {
		menu.removeClass('menu_fixed');
		socialbar.removeClass('menu_fixed');
	}
}