var photos = new Array;
photos[1] = new Image;
photos[2] = new Image;
photos[3] = new Image;
photos[1].src = '/img/photo1.jpg';
photos[2].src = '/img/photo2.jpg';
photos[3].src = '/img/photo3.jpg';

function getCookie(NameOfCookie){
  if (document.cookie.length > 0) {              
  begin = document.cookie.indexOf(NameOfCookie+"=");       
  if (begin != -1) {           
    begin += NameOfCookie.length+1;       
    end = document.cookie.indexOf(";", begin);
    if (end == -1) end = document.cookie.length;
      return unescape(document.cookie.substring(begin, end));
    } 
  }
  return null;
}

function setCookie(NameOfCookie, value, expiredays) {
  var ExpireDate = new Date ();
  ExpireDate.setTime(ExpireDate.getTime() + (expiredays * 24 * 3600 * 1000));
  document.cookie = NameOfCookie + "=" + escape(value) + 
  ((expiredays == null) ? "" : "; expires=" + ExpireDate.toGMTString());
}

function mod_photo () { 
  obj = document.getElementById('photo');
  var num = (Math.round(Math.random() * 2)) + 1; 
  newImg = photos[num].src;    
  if (preImg == newImg) { mod_photo(); } else { obj.src = newImg; }  
  return newImg;
}

function change_photo () {
  preImg = getCookie('preImg');
  if (preImg == null) { setCookie('preImg','/img/photo1.jpg',null) }    
  newImg = mod_photo();   
  setCookie('preImg',newImg,null);
}

function popup(s) {
  var win = window.open('/agreement.php?next=' + s, 'agreement', 'toolbar=0,location=0,directories=0,status=1,menubar=0,scrollbars=yes,resizable=yes,width=700,height=500');
  win.focus();    
}