bindTaskEvents not logging to console/ button errors

 editButton.onclick = editTask;

//problem:user interaction doesn't provide desired results
//solution: add interactivity
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


//add new task
var addTask = function () {
    console.log("Add task...");
    //when button is pressed, create new list item with text from #new_task:
    //input (checkbox)
    //label
    //input (text)
    //button.edit
    //button.delete
    //each elements, need to be modified and appended
}

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

    //toggle .editMode on the parent
}


//delete existing task
var deleteTask = function() {
    console.log("Add delete...");
    //when the delete button is pressed
    //remove the parent list item from the ul 

}

//mark task completed
var taskCompleted = function() {
    console.log("Task complete...");
    // when the Checkbox is checked
    //append the task list item to the #completed-tasks
}

//mark a task as incomplete
var taskIncomplete = function() {
    console.log("Task incomplete...");
    //when the checkbox is unchecked
    //append the task list item to the #completed-tasks
}

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");

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


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

    //bind deleteTask to delete button
    deleteButton.onclick = deleteTask;

    //bind checkBoxEventHandler to checkbox
    checkBox.onchange = checkBoxEventHandler;

    // cycle over incompleteTaskHolder ul lis

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

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