var dir = "sites/default/files/slideshow/";

function createDiv(images, parentdiv) {  
  var divTag = document.createElement("div");
  divTag.id = "my_gallery";  
  document.getElementById(parentdiv).appendChild(divTag);

  for(i=0;i<images.length;i++){
    createListItem(i,divTag.id,images[i]);
  }  
}

function createListItem(id,divID,imageName){
  var liTag = document.createElement("li");
  liTag.id = "li"+id;  
  document.getElementById(divID).appendChild(liTag);
  var imgTag = document.createElement("img");
  imgTag.setAttribute("alt","");
  imgTag.setAttribute("src",dir+imageName);
  document.getElementById(liTag.id).appendChild(imgTag);
}