function ingresar(){
	if(document.getElementById("presentacion")){
		document.getElementById('presentacion').style.visibility = "hidden";
		document.getElementById('presentacion').style.position = "absolute";
	}
	document.getElementById('container').style.visibility = "visible";
	document.getElementById('web').style.backgroundColor = "#ffffff";
}


function presentar(){
	window.scrollTo(0,0);
	var aumento_presentacion = 125; //800x600
	var y = window.innerHeight;
	var x = window.innerWidth;
	if( x <= 1024)
		document.getElementById("container").style.marginLeft = "0px";
	else
		document.getElementById("container").style.marginLeft = (x - 1024) / 2 + "px";

	if(document.getElementById("presentacion")){
		document.getElementById("presentacion").style.width = (y * aumento_presentacion / 100) + "px";
		document.getElementById("presentacion").style.height = y + "px";
		
		if(x <= 1024)
			document.getElementById("presentacion").style.marginLeft = (((y * aumento_presentacion / 100)) / 2) + "px";
		else
			document.getElementById("presentacion").style.marginLeft = ((x - (y * aumento_presentacion / 100)) / 2) + "px";

	}else{
		ingresar();
	}
}