Foto = new Array(5);
var num = 0;

Foto[0] = new Image();
Foto[1] = new Image();
Foto[2] = new Image();
Foto[3] = new Image();
Foto[4] = new Image();
Foto[5] = new Image();
Foto[6] = new Image();
Foto[7] = new Image();
Foto[8] = new Image();
Foto[9] = new Image();
Foto[10] = new Image();
Foto[11] = new Image();
Foto[12] = new Image();
Foto[13] = new Image();
Foto[14] = new Image();
Foto[15] = new Image();
Foto[16] = new Image();
Foto[0] = "/imgdesign/imagen1.jpg";
Foto[1] = "/imgdesign/imagen2.jpg";
Foto[2] = "/imgdesign/imagen3.jpg";
Foto[3] = "/imgdesign/imagen4.jpg";
Foto[4] = "/imgdesign/imagen5.jpg";
Foto[5] = "/imgdesign/imagen6.jpg";
Foto[6] = "/imgdesign/imagen7.jpg";
Foto[7] = "/imgdesign/imagen8.jpg";
Foto[8] = "/imgdesign/imagen9.jpg";
Foto[9] = "/imgdesign/imagen10.jpg";
Foto[10] = "/imgdesign/imagen11.jpg";
Foto[11] = "/imgdesign/imagen12.jpg";
Foto[12] = "/imgdesign/imagen13.jpg";
Foto[13] = "/imgdesign/imagen14.jpg";
Foto[14] = "/imgdesign/imagen15.jpg";
Foto[15] = "/imgdesign/imagen16.jpg";
Foto[16] = "/imgdesign/imagen16.jpg";

function PonerImagenes() 
{ 
//colocar el numero maximo + 1
num = getRandomNum(0, 17); 
document['Foto'].src=Foto[num]; 
} 
function getRandomNum(lbound, ubound) 
{
	return (Math.floor(Math.random() * (ubound - lbound)) + lbound);
}