// JavaScript Document
addLoadEvent(showHideNavigation);
addLoadEvent(initTopAnchors);
addLoadEvent(preloadImg);


function addLoadEvent(func) {
        var oldonload = window.onload;
        if (typeof window.onload != 'function') {
                window.onload = func;
        }
        else {
                window.onload = function() {
                        oldonload();
                        func();
                }
        }
}


/* show / hide navigation
***************************************************/
function showHideNavigation() {


        var navigation = $('navigation');
        var navigationBtn = $('btnNavigation');


        navigationBtn.onclick = function() {


                if (navigation.style.display=='none') {
                        navigationBtn.className='navigationToggleOpen';
                        Effect.BlindDown(navigation, { duration: .75 });
                } else {
                        navigationBtn.className='navigationToggleClosed';
                        Effect.BlindUp(navigation, { duration: .75 });
                }

        }
}





/* add a scroll action to every instance of backToTop links */
function initTopAnchors() {
        var btnLinks = $$('a.backToTop');
        for (i=0;i<btnLinks.length;i++) {
                btnLinks[i].onclick = function() {
                        Effect.ScrollTo('top');
                        return false;
                }
        }
}


function preloadImg() {
        if(document.images) {
          var image_array = new Array();

          // path to the directory with images
          var path = '../img/btn/';

          // enumeration of the "active" images
          image_array[0] = path + "englishE.png";
          image_array[1] = path + "englishA.png";
          image_array[2] = path + "deutschD.png";
          image_array[3] = path + "deutschA.png";
          image_array[4] = path + "gotoiTunes3.png";
          image_array[5] = path + "gotoiTunes4.png";
          image_array[6] = path + "btn_navigation_open_over.png";
          image_array[7] = path + "btn_navigation_open_off.png";
          image_array[8] = path + "btn_navigation_closed_over.png";
          image_array[9] = path + "btn_navigation_closed_off.png";

          var preload_image = new Array ();

          for(var i=0; i<image_array.length; i++)
          {
                preload_image[i]= new Image();
                preload_image[i].src = image_array[i];
          }
        }
}