var gallerycounter = 0;
function nextPicture(pictureName,titleCaption,galleryArr)
{
  if(galleryArr.length - gallerycounter > 1){
  	gallerycounter++;
  }else{
    gallerycounter = 0;
  }
  document.getElementById(pictureName).src = galleryArr[gallerycounter][0];
  document.getElementById(titleCaption).innerHTML = galleryArr[gallerycounter][1];
}

function prevPicture(pictureName,titleCaption,galleryArr)
{
  if(gallerycounter == 0){
  	gallerycounter = galleryArr.length - 1;
  }else{
    gallerycounter--;
  }
  document.getElementById(pictureName).src = galleryArr[gallerycounter][0];
  document.getElementById(titleCaption).innerHTML = galleryArr[gallerycounter][1];
}

function gotoPicture(pictureName,titleCaption,galleryArr,picNum)
{
  document.getElementById(pictureName).src = galleryArr[picNum][0];
  document.getElementById(titleCaption).innerHTML = galleryArr[picNum][1];
}