function moveToLeftImages() {
 firstVisibleImage=0;
 i=1;
    while(document.getElementById('imageli'+i)){
       img = document.getElementById('imageli'+i);
       if(img.style.display!="none") {
                  firstVisibleImage=i;
          break;
      }
       else {
          i++;
      }
   }
    if(firstVisibleImage>1) {
    i--;
    img = document.getElementById('imageli'+i);
    img.style.display = "inline";
    i = i+3;
    img = document.getElementById('imageli'+i);
    img.style.display = "none";
   }
}

function moveToRightImages() {
   firstVisibleImage=0;
    i=1;
  
    while(document.getElementById('imageli'+i)){
       img = document.getElementById('imageli'+i);
       if(img.style.display!="none") {
                  firstVisibleImage=i;
          break;
      }
       else {
          i++;
      }
   }
    i = firstVisibleImage+3;
      if(document.getElementById('imageli'+i)) {
            img = document.getElementById('imageli'+i);
            img.style.display = "inline";
            i = i-3;
            img = document.getElementById('imageli'+i);
            img.style.display = "none";
      }
}