function navi_preload() {
var navi_bg1 = new Image();
var navi_bg2 = new Image();
var navi_bg3 = new Image();
var navi_bg4 = new Image();
var navi_pfeil = new Image();

navi_bg1.src = "/bremenvier/_px/navigation.png";
navi_bg2.src = "/bremenvier/_px/navigation_themen.png";
navi_bg3.src = "/bremenvier/_px/navigation_events.png";
navi_bg4.src = "/bremenvier/_px/navigation_programm.png";
navi_pfeil.src = "/bremenvier/_px/icons/pfeile/button_rot.png";
}

function stn_btn_change( id_ref ) {
document.getElementById( id_ref ).src = "/bremenvier/_px/icons/pfeile/button_rot.png";
}

function stn_btn_reset( id_ref ) {
document.getElementById( id_ref ).src = "/bremenvier/_px/icons/pfeile/button_schwarz.png";
}

function close_navi() {
document.getElementById("musik_navi_content").style.display = "none"; 
document.getElementById("themen_navi_content").style.display = "none"; 
document.getElementById("events_navi_content").style.display = "none"; 
document.getElementById("ueber_uns_navi_content").style.display = "none"; 
}

function navi_bgr(bgr_nr) {
	var bgr_url;

	switch (bgr_nr) {
	case "c1" : document.getElementById("navi").style.backgroundImage = 'url("/bremenvier/_px/navigation.png")';
				document.getElementById("musik").style.zIndex=40;
				document.getElementById("themen").style.zIndex=30;
				document.getElementById("events").style.zIndex=20;
				document.getElementById("programm").style.zIndex=10;
				break;
	case "c2" : document.getElementById("navi").style.backgroundImage = 'url("/bremenvier/_px/navigation_themen.png")';
				document.getElementById("musik").style.zIndex=30;
				document.getElementById("themen").style.zIndex=40;
				document.getElementById("events").style.zIndex=20;
				document.getElementById("programm").style.zIndex=10;
				break;
	case "c3" : document.getElementById("navi").style.backgroundImage = 'url("/bremenvier/_px/navigation_events.png")';
				document.getElementById("musik").style.zIndex=10;
				document.getElementById("themen").style.zIndex=20;
				document.getElementById("events").style.zIndex=40;
				document.getElementById("programm").style.zIndex=30;
				break;
	case "c4" : document.getElementById("navi").style.backgroundImage = 'url("/bremenvier/_px/navigation_programm.png")';
				document.getElementById("musik").style.zIndex=10;
				document.getElementById("themen").style.zIndex=20;
				document.getElementById("events").style.zIndex=30;
				document.getElementById("programm").style.zIndex=40;
				break;
	default   : document.getElementById("navi").style.backgroundImage = 'url("/bremenvier/_px/navigation.png")';
				document.getElementById("musik").style.zIndex=40;
				document.getElementById("themen").style.zIndex=30;
				document.getElementById("events").style.zIndex=20;
				document.getElementById("programm").style.zIndex=10;
	}

}