function startSpel() {
x=10;
y=10;
width=700;
height=600;
if(window.screen){
 per_ancho=(width/800)*100;//porcentaje screen-ancho
 per_alto=(height/width)*100;//porcentaje de ancho-alto
 win_ancho=(screen.width*per_ancho)/100;//ancho de la ventana
 win_alto=(win_ancho*per_alto)/100;//alto de la ventana
 x=(screen.width-win_ancho)/2;//centra x
 y=(screen.height-win_alto)/2;//centra y
 y=y-40;
 if (y<0) {
  y=0;
  }
 }
s="spel/race.html";
w=window.open(s,"spel","width="+width+",height="+height+",left="+x+",top="+y+",resizable=0,status=1,toolbar=0,scrollbars=0");
if (window.screen) {
 w.focus();
 }
}