var what = null; 
var newbrowser = true; 
var check = false; 

function init() {  
	if (document.layers) {  
		layerRef="document.layers";  
		styleSwitch="";  
		visibleVar="show";  
		screenSize = window.innerWidth;  
		what ="ns4";  
	}  
	else if(document.all) {  
		layerRef="document.all";  
		styleSwitch=".style";  
		visibleVar="visible";  
		screenSize = document.body.clientWidth + 18;  
		what ="ie4";  
	}  
	else if(document.getElementById) {  
		layerRef="document.getElementByID";  
		styleSwitch=".style";  
		visibleVar="visible";  
		what="dom1";  
	}  
	else {  
		what="none";  
		newbrowser = false;  
	} 
	check = true; 
} 
 
 function showLayer(layerName) {  
	 if(check) {  
		 if (what =="none") {  
			 return;  
		 }  
		 else if (what == "dom1") {  
		 	document.getElementById(layerName).style.visibility="visible";  
		}  
		else {  
			eval(layerRef+'["'+layerName+'"]'+styleSwitch+'.visibility="visible"');  
		}  
	}  
	else {  
		return;  
	}  
} 

function hideLayer(layerName) {  
	if(check) {  
		if (what =="none") {  
			return;  
		}  
		else if (what == "dom1") {  
			document.getElementById(layerName).style.visibility="hidden";  
		}  
		else {  
			eval(layerRef+'["'+layerName+'"]'+styleSwitch+'.visibility="hidden"');  
		}  
	}  
	else {  
		return;  
	}  
} 

function hideAll() {  
	hideLayer('mieszkania');  
	hideLayer('domy');  
	hideLayer('dzialki');  
} 

function layera() {
	hideAll();
	showLayer(document.forms['typek'].typ.value);
}

function onLoad() {  
	init();  
}