// JavaScript Document

// Array, which contains all available images 
// to add a new image change the appropriate Array image_arr
var image_arr = new Array(  "img1",
						    "img2",
							"img3",
							"img4",
							"img5",
							"img6",
							"img7",
							"img8",
							"img9",
							"img10",
							"img11",
							"img12",
							"img13",
							"img14",
							"img15" );

// function to present dynamically a picture on the right hand of the page 
// therefore a random function is used
function get_picture(){
  var len = image_arr.length-1;
  // get a image using the random function
  var result = image_arr[Math.round(Math.random() * len)];
  return result;
}