I get only one box, and I had to change editInput to taskInput on line 29, in the appending section

// Problem: User interaction does notprovice 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 incompleteTaskHolder = document.getElementById("incomplete-tasks"); 
var completedTaskHolder= document.getElementById("completed-tasks"); // 


// New task list button
var createNewtaskElement = function(taskString) { 
// Create list Iem
var listItem = document.createElement("li");
  // inout checkbox
  var checkBox = document.createElement("input");
  // label
var label = document.createElement("label");
  // input (text)
 var input = document.createElement("input");
  // button.edit
var editButton = document.createElement("button");  
// button.delete
var deleteButton = document.createElement("button");

// Each element needs modifing 
// Each element needs appending
listItem.appendChild(checkBox);  
listItem.appendChild(label);  
listItem.appendChild(taskInput);  
listItem.appendChild(editButton);  
listItem.appendChild(deleteButton);  

return listItem;
}

// Add new task
var addTask = function() {
  console.log("addTask...")
 // create a new list item form the text fron "new-task
 var listItem = createNewtaskElement("Some New task"); 

  // Append listItem to IncompleteTaskHolder
  incompleteTaskHolder.appendChild(listItem);
}

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

  // Toggle .editmode
}

// delete task
var deleteTask = function() {
  console.log("deleteTask...")
  // When deldete button is pressed 
      // remove parent list item form the unordered list

}

// mark complete
var taskComplete = function() {
    console.log("completeTask...")
  // When the checkbox is checked 
    // Append the task list item to the #completed-tasks
}

// mark incomplete
var taskIncomplete = function() { 
    console.log("incompleteTask...")
  // When the cjeckbox is unchecked
    // Append to #incomplete=tasks
}

var bindTaskEvents= function(taskListItem, checkBoxEventHandler) {
console.log("Bind list items events")

  // Select iliItem's  children
  var checkBox = taskListItem.querySelector("input[type=checkbox");
  var editButton = taskListItem.querySelector("button.edit");   
  var deleteButton = taskListItem.querySelector("button.delete"); 
//Bind the next task to editTask to EditButton
  editButton.onclick = editTask;
  // bind DeletedTask to Delet Button
  deleteButton.onclick = deleteTask;

  // Bind checkBoxEventHandler to the checkbox
  checkBox.onchange = checkBoxEventHandler;
}

// Set the click handler to the AddTask function


// Cycle over the incompleteTaskHolder ul List items
addButton.onclick = addTask;
for(var i = 0; i < incompleteTaskHolder.children.length; i++) {
  //Bind the next task to editTask to EditButton
  bindTaskEvents(incompleteTaskHolder.children[i], taskComplete);
}
// For reach list items childern {taskcompleted}


// Cycle over the completeTaskHolder ul List items
for(var i = 0; i < completedTaskHolder.children.length; i++) {
  //Bind the next task to editTask to EditButton
  bindTaskEvents(completedTaskHolder.children[i], taskIncomplete);
}

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

listItem.appendChild(taskInput);