function init() 
{
	toggleNavOnLoad();
	adjustHeight();
}

function toggleNav(elementId)
{
	if (document.getElementById("navAlgemeen") != null) {
		document.getElementById("navAlgemeen").style.display = "none";
	}
	if (document.getElementById("navActueel") != null) {
		document.getElementById("navActueel").style.display = "none";
	}
	if (document.getElementById("navBeheer") != null) {
		document.getElementById("navBeheer").style.display = "none";
	}
	if (document.getElementById("navMijnKlasse") != null) {
		document.getElementById("navMijnKlasse").style.display = "none";
	}
	if (document.getElementById(elementId) != null) {
		document.getElementById(elementId).style.display = "block";
	}
}

function toggleNavOnLoad()
{
	var url = document.location.href;

	if (url.indexOf('/algemeen/') != -1) { toggleNav("navAlgemeen"); };

	if (url.indexOf('/actueel/') != -1) { toggleNav("navActueel"); };
	if (url.indexOf('/documenten/') != -1) { toggleNav("navActueel"); };
	if (url.indexOf('/fotos/') != -1) { toggleNav("navActueel"); };
	if (url.indexOf('/nieuws/') != -1) { toggleNav("navActueel"); };
	if (url.indexOf('/wedstrijden/') != -1) { toggleNav("navActueel"); };
	
	if (url.indexOf('/admin/') != -1) { toggleNav("navBeheer"); };
	if (url.indexOf('/admin/bestuur/') != -1) { toggleNav("navBeheer"); };
	if (url.indexOf('/admin/redactie/') != -1) { toggleNav("navBeheer"); };
	if (url.indexOf('/admin/site') != -1) { toggleNav("navBeheer"); };
	if (url.indexOf('/admin/wedstrijden/') != -1) { toggleNav("navBeheer"); };
	if (url.indexOf('/admin_bestuur/') != -1) { toggleNav("navBeheer"); };
	if (url.indexOf('/admin_zeilen/') != -1) { toggleNav("navBeheer"); };
	
	if (url.indexOf('/users/') != -1) { toggleNav("navMijnKlasse"); };
}

function adjustHeight()
{
	// Calculate the height of the header. 
    var headerHeight = 0; 
    var header = document.getElementById("header"); 
    if (header != null) { headerHeight = header.offsetHeight; };

    // Calculate the height of the footer section. 
    var footerHeight = 0; 
    var footer = document.getElementById("footer"); 
    if (footer != null) { footerHeight = footer.offsetHeight; };
	
	// Calculate the height of the main section.
	var mainHeight = 0;
	var main = document.getElementById("main-copy");
    if (main != null) { mainHeight = main.offsetHeight; };

	// Calculate the height of application components that are always visible. 
    var applicationHeight = headerHeight + footerHeight; 

	// Calculate the height of the actual window.
	var windowHeight = 0;
	if ( parseInt( navigator.appVersion ) > 3 ) {
	 	if ( navigator.appName.indexOf("Microsoft") != -1 ) {
			windowHeight = document.body.offsetHeight;
	 	}
		else {
			//windowHeight = window.outerHeight;
			windowHeight = document.body.offsetHeight;
	 	};
	}

	// Target height for the remainder of the screen is the browser height 
    // minus the height of the fixed components.
    var targetHeight = windowHeight - applicationHeight;
	
	// Now sets the height of the main section if necessery.
	if ( main != null ) { 
		if (windowHeight > applicationHeight + mainHeight) {
			main.style.height = targetHeight + "px";
		};
	};
}