It's Not Working?

//Proble: user interaction does not provide results
//Solution: Add interavtivity so user can add 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 element needs modifying

    //Each element needs appeneding

   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);

 }

//Edit an existing task
 var editTask = function() {
   console.log("edit task...");
  //when the edit button is pressed
// if the class of the parent is the .editmode
//switch from edit mode 
//label text become the input value
//else
//switch to edit mode
//input value becomes the labels text

//toggel edit mode on the parent
 }
//Delete an existing task
 var deleteTask = function() {
   console.log("delete task...");
  //when the delete button is pressed
  //remove the parent list item from the ul list
 }

//Mark a task as complete
var taskCompleted = function() {
  console.log(" task complete...");
//append the task list item to the completed tasts
  var listItem = this.parentNode;
  completedTasksHolder.appendChild(this.parentNode);
}

//Mark a task as incomplete
var taskIncomplete = function () {
  console.log("task incomplete...");
  //when the check box is unchecked 
  //we want to appent to the completed tasks
  var listItem = this.parentNode;
  incompleteTasksHolder.appendChild(listItem);


}

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

  //bind the edit task to edit button
  editButton.onclick = editTask;

  //bind deleteTask to delete button
  deleteButton.onclick = deleteTask;
  //bind checkBoxEventHandler to the check box
  checkBox.onchange = checkBoxEventHandler;
}
//set the click handler to the addTask function
addButton.onclick = addTask;

//cycle over incompleteTaskHolder ul list items
for(var i = 0; i < incompleteTasksHolder.children.length; i++);{

    //bind events to list item children(taskcompleted)
  bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted);
}

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

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