var core = 0;

function StringArray (n) {
  this.length = n;
  for (var i =1; i <= n; i++) {
    this[i] = ' ';

  }
}

image = new StringArray(2);
image[0] = 'http://www.gentle.ch/fileadmin/bilder/herren-startseite.jpg';
image[1] = 'http://www.gentle.ch/fileadmin/bilder/frauen-startseite.jpg';

function ranimage() {
	core = Math.floor(Math.random()*image.length);
    return(image[core]);
}

document.write("<img id='Bild' usemap='#Map' src='" +ranimage()+ "'>");



function frauen () {
    document.getElementById("Bild").src = "http://www.gentle.ch/fileadmin/bilder/frauen-startseite.jpg";
    return;
  }
	
	function herren () {
    document.getElementById("Bild").src = "http://www.gentle.ch/fileadmin/bilder/herren-startseite.jpg";
    return;
  }