function BrowserCheck() {
	var b = navigator.appName
	if (b=="Netscape") this.b = "ns"
	else if (b=="Microsoft Internet Explorer") this.b = "ie"
	else this.b = b
	this.version = navigator.appVersion
	this.v = parseInt(this.version)
	this.ns = (this.b=="ns" && this.v>=4)
	this.ns4 = (this.b=="ns" && this.v==4)
	this.ns5 = (this.b=="ns" && this.v==5)
	this.ie = (this.b=="ie" && this.v>=4)
	this.ie4 = (this.version.indexOf('MSIE 4')>0)
	this.ie5 = (this.version.indexOf('MSIE 5')>0)
	this.min = (this.ns||this.ie)
}

is = new BrowserCheck()
cargada=false;
function preloadimg(imgDocID,imgSrca,imgSrcb) {
	if (document.images) 
	{
		eval(imgDocID+'a = new Image()')
		eval(imgDocID+'b = new Image()')
		eval(imgDocID+'a.src = "'+imgSrca+'"')
		eval(imgDocID+'b.src = "'+imgSrcb+'"')
	}
}
activo = '';
function dentro2(capa,imgDocID) {
	if (document.images && cargada)
	{
    if (activo != "") {  changeImage(capa,imgDocID,imgDocID+'b'); activo='';}
	changeImage(capa,imgDocID,imgDocID+'b');
    activo = imgDocID;
	}
	}
function fuera2(capa,imgDocID) {
	if (document.images && cargada)
	{
	changeImage(capa,imgDocID,imgDocID+'a');
    activo = '';
	}
	}

function changeImage(layer,imgName,imgObj) {
	if (document.images && cargada) {
		if (document.layers && layer!=null) eval('document.'+layer+'.document.images["'+imgName+'"].src = '+imgObj+'.src')
		else document.images[imgName].src = eval(imgObj+".src")
	}
}	
function dentro(imgDocID) {
	if (document.images && cargada)
	{
    if (activo != "") { document.images[activo].src = eval(activo + "a.src"); activo='';}
    document.images[imgDocID].src = eval(imgDocID + "b.src");
    activo = imgDocID;
	}
	}
function fuera(imgDocID) {
	if (document.images && cargada)
	{
    document.images[imgDocID].src = eval(imgDocID + "a.src")
    activo = '';
	}
	}