function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}

function geodesyThemeOneNext()
{
    var imgDst = document.getElementById('geodesy-theme-1');
    var temp = imgDst.getAttribute('src');
    var patern = /geodesy_theme_0([1-4]).jpg/
    imgNum = parseInt(temp.match(patern)[1]);
    if(imgNum < 4)
    {
        imgNum++;
    }
    else
    {
        imgNum = 1;
    }

    var imgSrc = "images/"; 
    imgSrc += "geodesy_theme_0" + imgNum + ".jpg";
    imgDst.setAttribute("src", imgSrc);
}

function geodesyThemeTwoNext()
{
    var imgDst = document.getElementById('geodesy-theme-2');
    var temp = imgDst.getAttribute('src');
    var patern = /geodesy_theme_0([5-8]).jpg/
    imgNum = parseInt(temp.match(patern)[1]);
    if(imgNum < 8)
    {
        imgNum++;
    }
    else
    {
        imgNum = 5;
    }

    var imgSrc = "images/"; 
    imgSrc += "geodesy_theme_0" + imgNum + ".jpg";
    imgDst.setAttribute("src", imgSrc);
}



function galleryNext()
{
	if( typeof galleryNext.counter == 'undefined' ) {
        galleryNext.counter = 0;
    }
	if(galleryNext.counter == 0){
		geodesyThemeOneNext();
		galleryNext.counter = 1;
	}
	else {
		geodesyThemeTwoNext();
		galleryNext.counter = 0;
	}
}