// JavaScript Document

function popUp(URL) {
day = new Date();
id = day.getTime();
eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=730,height=500,left = 275,top = 150');");
}
<!-- Pop up --> 


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() {
	if (document.images) {
		//alert('dentro de preloadImages');
		m1_acerca_over = newImage("images/m1_acerca-over.jpg");
		m2_soluciones_over = newImage("images/m2_soluciones-over.jpg");
		m3_info_inver_over = newImage("images/m3_info_inver-over.jpg");
		m4_estrategias_over = newImage("images/m4_estrategias-over.jpg");
		m5_directorio_over = newImage("images/m5_directorio-over.jpg");
		m6_contacto_over = newImage("images/m6_contacto-over.jpg");
		mi_1_02_over = newImage("images/mi_1_02-over.jpg");
		mi_1_03_over = newImage("images/mi_1_03-over.jpg");
		mi_1_04_over = newImage("images/mi_1_04-over.jpg");
		preloadFlag = true;
	}
}