window.onload = choosePic;



var myPix = new Array("img/schoolpic/01.jpg", "img/schoolpic/02.jpg" , "img/schoolpic/05.jpg" ,"img/schoolpic/06.jpg", "img/schoolpic/07.jpg");

function choosePic() {

      randomNum = Math.floor((Math.random() * myPix.length));

      document.getElementById("myPicture").src = myPix[randomNum];

}