New Items don't appear properly

// Problem: user interaction doesn't provide desired results.
// Solution: add interactivity so the user can manage daily tasks.

var taskInput = document.getElementById("new-task"); //new-task
var addButton = document.getElementsByTagName("button")[0]; //first-button
var incompleteTasksHolder = document.getElementById("incomplete-tasks"); //incomplete-tasks
var completedTasksHolder = document.getElementById("completed-tasks"); //completed-tasks

//New Task List Item
var createNewTaskElement = function(taskString) {
  // Create List item
  var listItem = document.createElement("li");

  //input (checkbox)
  var checkBox = document.createElement("input"); //checkbox

  //label
  var label = document.createElement("label"); 

  //input (text)
  var editInput = document.createElement("input"); //text

  //button.edit
  var editButton = document.createElement("button");

  //button.delete
  var deleteButton = document.createElement("button");

  // each elements need to modifying 
  checkBox.type = "checkbox";
  editInput.type = "text";

  editButton.innerHTML = "Edit";
  editButton.classList = "edit";
  deleteButton.innerHTML = "Delete";
  deleteButton.className = "delete";

  label.innerText = taskString; 

  // each elements neet to appending
  listItem.appendChild(checkBox);
  listItem.appendChild(label);
  listItem.appendChild(editInput);
  listItem.appendChild(editButton);
  listItem.appendChild(deleteButton);
  return listItem;
}

// Add a new task
var addTask = function() {
  console.log("Add task...");
  //create a new list item with the text from #new-task
  var listItem = createNewTaskElement("Some New Task");

  // Append listItem to incompleteTaskHolder
  incompleteTasksHolder.appendChild(listItem);
  bindTaskEvents(listItem, taskCompleted);
  }

// Edit an existing task
var editTask = function() {
  console.log("Edit Task...");
  //when the edit button is pressed
    //if the class of the parend is .editMode
      //switch from .editMode
      //label text becom the input's value
    //else
      //switch to .editMode
      //input value becomes the label's text

      // toggle .editMode on the parent
}

// Delete an existing task
var deleteTask = function() {
  console.log("Delete task...");
  var listItem = this.parentNode;
  var ul = listItem.parentNode;

  //remove the parent list item from the ul
  ul.removeChild(listItem);
}

// Mark a task as complete
var taskCompleted = function() {
  console.log("Task completed...");

  //append the task list item to the #completed-tasks
  var listItem = this.parentNode;
  completedTasksHolder.appendChild(listItem);
  bindTaskEvents(listItem, taskIncomplete);
}

// Mark a task as incomplete
var taskIncomplete = function() {
  console.log("Task incomplete...");

  //when the task list list item to the #incomplete-tasks
  var listItem = this.parentNode;
  incompleteTasksHolder.appendChild(listItem);
  bindTaskEvents(listItem, taskCompleted);
}

var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
  console.log("Bind list item events");
  // select taskListItem's children
  var checkBox = taskListItem.querySelector("input[type=checkbox]");
  var editButton = taskListItem.querySelector("button.edit");
  var deleteButton = taskListItem.querySelector("button.delete");

    // bind editTask to edit button
  editButton.onclick = editTask;
    // bind deleteTask to delete button
  deleteButton.onclick = deleteTask;
    // bind  checkBoxEventHandler to checkbox
  checkBox.onchange = checkBoxEventHandler;
}

// Set the click handler to the addTask function
addButton.onclick = addTask;

// cycle over incompleteTasksHolder ul list items
for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted)
}

// cycle over completedTasksHolder ul list items
for(var i = 0; i < completedTasksHolder.children.length; i++) {
  //bind events to list item's children (taskIncomplete)
  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete)
}