function VecImagenes()
    {
    n=0;
    this[n++]="img/img_top_01.gif";
    this[n++]="img/img_top_02.gif";
    this[n++]="img/img_top_03.gif";
    this[n++]="img/img_top_04.gif";
    this[n++]="img/img_top_05.gif";
    this[n++]="img/img_top_06.gif";
    this[n++]="img/img_top_07.gif";
    this[n++]="img/img_top_08.gif";
    this[n++]="img/img_top_09.gif";
    this[n++]="img/img_top_10.gif";
    this.N=n;
    }
var Imagenes=new VecImagenes();
src= Imagenes[ Math.floor(Math.random() * Imagenes.N) ] ;
document.write("<img src="+src+">");