var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		pre_b_quienes_over = newImage('images/botones/b-quienes-over.jpg');
		pre_b_ejemplos_over = newImage('images/botones/b-ejemplos-over.jpg');
		pre_b_beneficios_over = newImage('images/botones/b-beneficios-over.jpg');
		pre_b_impreso_over = newImage('images/botones/b-impreso-over.jpg');
		pre_b_ejercicios_over = newImage('images/botones/b-ejercicios-over.jpg');
		pre_b_precios_over = newImage('images/botones/b-precios-over.jpg');
		pre_b_contactenos_over = newImage('images/botones/b-contactenos-over.jpg');
		preloadFlag = true;
	}
}

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

userAgent = window.navigator.userAgent;
browserVers = parseInt(userAgent.charAt(userAgent.indexOf("/")+1),10);
mustInitImg = true;
function initImgID() {var di = document.images; if (mustInitImg && di) { for (var i=0; i<di.length; i++) { if (!di[i].id) di[i].id=di[i].name; } mustInitImg = false;}}

function findElement(n,ly) {
    var d = document;
    if (browserVers < 4)        return d[n];
    if ((browserVers >= 6) && (d.getElementById)) {initImgID; return(d.getElementById(n))}; 
    var cd = ly ? ly.document : d;
    var elem = cd[n];
    if (!elem) {
        for (var i=0;i<cd.layers.length;i++) {
            elem = findElement(n,cd.layers[i]);
            if (elem) return elem;
        }
    }
    return elem;
}

function changeImagesArray(array) {
    if (preloadFlag == true) {
        var d = document; var img;
        for (i=0;i<array.length;i+=2) {
            img = null; var n = array[i];
            if (d.images) {
                if (d.layers) {img = findElement(n,0);}
                else {img = d.images[n];}
            }
            if (!img && d.getElementById) {img = d.getElementById(n);}
            if (!img && d.getElementsByName) {
                var elms = d.getElementsByName(n);
                if (elms) {
                    for (j=0;j<elms.length;j++) {
                        if (elms[j].src) {img = elms[j]; break;}
                    }
                }
            }
            if (img) {img.src = array[i+1];}
        }
    }
}

function changeImages() {
    changeImagesArray(changeImages.arguments);
}