while(true){
aleatorio = Math.random();
numero = Math.round(aleatorio * 14);

if (numero == 0){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/5_110.jpg";
break;}

if (numero == 1){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/410.jpg";
break;}

if (numero == 2){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/14_110.jpg";
break;}

if (numero == 3){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/flamme10.jpg";
break;}

if (numero == 4){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/1_110.jpg";
break;}

if (numero == 5){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/110.jpg";
break;}

if (numero == 6){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/7_110.png";
break;}

if (numero == 7){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/210.jpg";
break;}

if (numero == 8){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/3_110.jpg";
break;}

if (numero == 9){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/310.jpg";
break;}

if (numero == 10){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/4_110.jpg";
break;}

if (numero == 11){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/510.jpg";
break;}

if (numero == 12){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/6_110.jpg";
break;}

if (numero == 13){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/710.jpg";
break;}

if (numero == 14){
imagen = "https://i.servimg.com/u/f33/15/43/37/17/8_110.jpg";
break;}
}
document.getElementsByTagName('body')[0].style.backgroundImage = "url(" + imagen + ")"