function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;

function preloadImages(lang) {
	if (document.images) {
		var b1 = newImage("./gfx/menu/start_active_"+lang+".jpg");
		var b2 = newImage("./gfx/menu/flota_active_"+lang+".jpg");
		var b3 = newImage("./gfx/menu/glownekierunki_active_"+lang+".jpg");
		var b4 = newImage("./gfx/menu/ofirmie_active_"+lang+".jpg");
		var b5 = newImage("./gfx/menu/kontakt_active_"+lang+".jpg");
		preloadFlag = true;
	}
}

function getWindowHeight() {
	if( typeof( window.innerWidth ) == 'number' ) {
	   	return window.innerHeight;
	} else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
		return document.documentElement.clientHeight;
	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
		return document.body.clientHeight;
	} else {
		return 0;
	}
}

function disableBg() {
	var WH = getWindowHeight();
	var GH = document.getElementById('global').offsetHeight;
	
	if(WH > GH) 
		var H = WH;
	else 
		var H = GH;
	
	document.getElementById('hideScreen').style.height = H+'px';
	document.getElementById('hideScreen').style.display = 'block';	
}

function enableBg() { 
	document.getElementById('hideScreen').style.display	= 'none';
	document.getElementById('popup').style.display	= 'none';
};

function show_form() {
	disableBg();
	document.getElementById('popup').style.display = 'block';
}

function clear_form() {
	document.getElementById('contact_form').reset();
	if(e = document.getElementById('komunikat'))
		e.innerHTML = '';
}