function initArray() {
        
this.length = initArray.arguments.length;
  for (var i = 0; i < this.length; i++) {
  this[i] = initArray.arguments[i];
  }
}

image = new initArray(
"logos/logogrande-01.jpg",
"logos/logogrande-02.jpg",
"logos/logogrande-03.jpg",
"logos/logogrande-04.jpg",
"logos/logogrande-05.jpg",
"logos/logogrande-06.jpg",
"logos/logogrande-07.jpg",
"logos/logogrande-08.jpg",
"logos/logogrande-09.jpg",
"logos/logogrande-10.jpg",
"logos/logogrande-11.jpg",
"logos/logogrande-12.jpg",
"logos/logogrande-13.jpg",
"logos/logogrande-14.jpg",
"logos/logogrande-15.jpg",
"logos/logogrande-16.jpg",
"logos/logogrande-17.jpg",
"logos/logogrande-18.jpg",
"logos/logogrande-19.jpg",
"logos/logogrande-20.jpg",
"logos/logogrande-21.jpg",
"logos/logogrande-22.jpg",
"logos/logogrande-23.jpg",
"logos/logogrande-24.jpg",
"logos/logogrande-25.jpg",
"logos/logogrande-26.jpg",
"logos/logogrande-27.jpg",
"logos/logogrande-28.jpg",
"logos/logogrande-29.jpg",
"logos/logogrande-30.jpg",
"logos/logogrande-31.jpg",
"logos/logogrande-32.jpg",
"logos/logogrande-33.jpg",
"logos/logogrande-34.jpg",
"logos/logogrande-35.jpg",
"logos/logogrande-36.jpg",
"logos/logogrande-37.jpg",
"logos/logogrande-38.jpg",
"logos/logogrande-39.jpg",
"logos/logogrande-40.jpg",
"logos/logogrande-41.jpg",
"logos/logogrande-42.jpg"
);

var cantidadDecimales = 2;
var cantidadDecimales = cantidadDecimales+2;
var numero = Math.random();
var numero = ''+numero+'';
var numero = numero.substring(2,cantidadDecimales);
var numero = numero % image.length;
var ranimage = image[numero];
document.write('<img src=\"'+ranimage+'\" border="0"><br>');