var CurrentMenuItem;

function get_content(source, menu, options, target) {
	var xmlHttp = null;
	
	if(target  == undefined) target  = 'source_maincontent';
	if(options == undefined) options = '';
		else options = "?" + options;

	try {
	    // Mozilla, Opera, Safari sowie Internet Explorer (ab v7)
	    xmlHttp = new XMLHttpRequest();
	} catch(e) {
	    try {
	        // MS Internet Explorer (ab v6)
	        xmlHttp  = new ActiveXObject("Microsoft.XMLHTTP");
	    } catch(e) {
	        try {
	            // MS Internet Explorer (ab v5)
	            xmlHttp  = new ActiveXObject("Msxml2.XMLHTTP");
	        } catch(e) {
	            xmlHttp  = null;
	        }
	    }
	}
	if (xmlHttp) {
	    xmlHttp.open('GET', source + '.php' + options, true);
	    xmlHttp.onreadystatechange = function () {
	        if (xmlHttp.readyState == 4) {
            	if (menu == true) {
		            window.CurrentMenuItem = source;
            		set_content_menuitem(CurrentMenuItem);
            	} 
	            write_content(xmlHttp.responseText, target);
	        }
	    };
	    xmlHttp.send(null);
	}
}

function write_content(response, target) {
	document.getElementById(target).innerHTML = response;
}

function set_content_menuitem(source) {
	var imgs = document.images;
	
	//Menutitems zurücksetzen
	for (var i = 0, l = imgs.length; i < l; i++) {
		if (imgs[i].id.substring(0,10) == 'menu_item_') {

			if (imgs[i].id.substring(imgs[i].id.length - 5, imgs[i].id.length) == "arrow") {
				var item = imgs[i].id.split("_");
				if (item[2] != CurrentMenuItem) {
					document.getElementById("menu_item_" +item[2]+ "_arrow_").style.display = "none";
					document.getElementById("menu_item_" +item[2]+ "_arrow").src = "images/player_vor.png";

					document.getElementById("menu_item_" +item[2]+ "_arrow_footer_").style.display = "none";
					document.getElementById("menu_item_" +item[2]+ "_arrow_footer").src = "images/player_vor.png";
				}
			}
			
			if (imgs[i].id.substring(imgs[i].id.length - 3, imgs[i].id.length) == "img") {
				var item = imgs[i].id.split("_");
				if (item[2] != CurrentMenuItem) {
					document.getElementById("menu_item_" +item[2]+ "_img").src = "images/" +item[2]+ ".png";
					document.getElementById("menu_item_" +item[2]+ "_img_footer").src = "images/" +item[2]+ ".png";
				}
			}

		}
	}

	//Item setzen
	if (source != 'reset') {
		document.getElementById("menu_item_" +source+ "_arrow_").style.display = "block";
		document.getElementById("menu_item_" +source+ "_arrow_footer_").style.display = "block";
	
		//Menü
		document.getElementById("menu_item_" +CurrentMenuItem+ "_arrow").src = "images/player_vor_hover.png";
		document.getElementById("menu_item_" +CurrentMenuItem+ "_arrow_").style.display = "block";
		document.getElementById("menu_item_" +CurrentMenuItem+ "_img").src = "images/" +CurrentMenuItem+ "_hover.png";
	
		//Footer
		document.getElementById("menu_item_" +CurrentMenuItem+ "_arrow_footer").src = "images/player_vor_hover.png";
		document.getElementById("menu_item_" +CurrentMenuItem+ "_arrow_footer_").style.display = "block";
		document.getElementById("menu_item_" +CurrentMenuItem+ "_img_footer").src = "images/" +CurrentMenuItem+ "_hover.png";
	}
}