Edit Button is not working.. And how could it?..

//Problem: User interaction doesn't provide desired results.
//Solution: Add interactivty 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");                                                
    //label
var label = document.createElement("label");                                                
    //input (text)
var editInput = document.createElement("input");                                                
    //button.edit
var editButton = document.createElement("button");                                                
    //button.delete
var deleteButton = document.createElement("button");                                                
    //Each elements, needs modified 

 checkBox.type = "checkbox";
    editInput.type = "text";

    label.innerHTML = taskString;

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


    //and appended
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(taskInput.value);

  // Append List item to incompleteTasksHolder
  incompleteTasksHolder.appendChild(listItem);


}

//Edit an existing task
var editTask = function() {
  console.log("Edit task...");

  var listItem = this.parentNode;

  var editInput = listItem.querySelector("input[type=text");
  var label = listItem.querySelector("label");

  var containsClass = listItem.classList.contains("editMode");

  //if the class of the parent is .editMode
  if(containsClass) {
    //Switch from .editMode
    //label text become the input's value
    label.innerText = editInput.value;
  } else {
    //Switch to .editMode
    //input value becomes the label's text
    editInput.value = label.innerText;
  }

  //Toggle .editMode on the list item
  listItem.classList.toggle("editMode");

};

//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
}

//Mark a task as complete
var taskCompleted = function() {
  console.log("Task complete...");
    //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...");
    //Append the task 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 incompleteTaskHolder ul li items
for(var i = 0; i < incompleteTasksHolder.children.length; i++) {

  bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted);
};


    // for each list item
      // bind events to list items children ( taskCompleted)



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