var browser_typ="unknown";
var hide_code="hidden";
var show_code="visible";
var layer_handle;
var layer_visibility;
var layer_image_base;
var last_menu_visible="";
var last_menu_intro_visible="";
var last_detail_visible="";

function showlayer(id){
    get_layer_handle(id);
    layer_visibility.visibility=show_code;
}

function hidelayer(id){
    get_layer_handle(id);
    layer_visibility.visibility=hide_code;
}

function get_layer_handle(id) {
    if(document.all){
		if(document.all[id]){
	 	   browser_typ="ie";
		    show_code="visible";
		    hide_code="hidden";
		    layer_visibility=document.all[id].style;
		    layer_handle = document.all[id];
		    layer_image_base=document.images;
		    return layer_handle;
		} else {
			//alert("BR3: no layer with name "+id);
		}
    } else if(document.layers){
		if(document.layers[id]){
			browser_typ="netscape";
			show_code="visible";
			hide_code="hidden";
			layer_visibility=document.layers[id];
	    	layer_handle=document.layers[id];
	    	layer_image_base=layer_handle.document.images;
	    	return layer_handle;
	   } else {
	   	//alert("BR2: no layer with name "+id);
	   }
    } else if(document.documentElement || document.getElementById){
     	if(document.getElementById(id)){
			browser_typ="ECMA";
			show_code="visible";
			hide_code="hidden";
			layer_visibility=document.getElementById(id).style;
			layer_handle=document.getElementById(id);
			layer_image_base=null;
			return layer_handle;
     	} else {
		//alert("BR1: no layer with name "+id);
	}
    } else {
     //alert('Browser unknown !!!!');
    }
}

function get_layer_image_base(id,imgname) {
    if( document.getElementById && document.getElementById(id) ){
	myvar=document.getElementById(imgname);
	return myvar;
    } else {
	get_layer_handle(id);
	return layer_image_base[imgname];
    }
}