Receiving and 'editButton is not defined' error

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 a new task
var addTask = function() {
  console.log("Add Task...");
  //When the button is pressed

    //Create a new list item with the text from #new-task:
      //input (checkbox)
      //label
      //input (text)
      //button.edit
      //button.delete
      //Each elements, needs modified and appended
}

//Edit an existing task
var editTask = function() {
   console.log("Edit Task...");
  //When the Edit button is pressed
    //if the class of the parent is .editNode
      //Switch from .editMode
      //Label text bcomes the input's value
    //else
      //Switch to .editMode
      //input value becomes the labe's text

    //Toggle .editMode on the parent
}

//Delete and existing task
var deleteTask = function() {
   console.log("Delete Task...");
  //When the delet button is pressed
    //Remove the paent list item from the ul
}

//Mark a task as complete
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 Complete...");
  //When the chckbox is unchecked
    //Append the task list itme to the #incomplete-tasks
}

var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
  console.log("Task incomplete...");
  //select it'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
    //bind deleteTask to the delete button
    //bind checkBoxEventHandler to the checkbox
}


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

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

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

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

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

'''

Ha! I think I corrected it - I was assigning the onclick event handlers outside of the bindTaskEvents function, so the handlers were not getting assigned at each iteration during the for loops as they should have been!