JS Double Linked List

function TaskNode(task) { 
    this.taskName = task.name; 
    this.taskUri = task.id
    this.nextTask = null; 
    this.previousTask = null; 
} 

function WorkflowTaskLinkedList() { 
    this.head = new TaskNode({name:"head",id:'http://123'}); 
    this.find = find; 
    this.insert = insert; 
    this.remove = remove; 
    this.findLast = findLast; 
} 
function findLast() { 
    var currNode = this.head; 
    while (!(currNode.nextTask == null)) { 
        currNode = currNode.nextTask; 
    } 
    return currNode; 
} 
function remove(item) { 
    var currNode = this.find(item); 
    if (!(currNode.next == null)) { 
        currNode.previousTask.nextTask = currNode.nextTask; 
        currNode.nextTask.previousTask = currNode.previousTask; 
        currNode.nextTask = null; 
        currNode.previousTask = null; 
    } 
} 
function find(item) { 
    var currNode = this.head; 
    while (currNode.taskName != item.name) { 
        currNode = currNode.nextTask; 
    } 
    return currNode; 
} 
function insert(newTask, item) { 
    var newNode = new TaskNode(newTask); 
    var current = this.find(item); 
    newNode.nextTask = current.nextTask; 
    newNode.previousTask = current; 
    current.nextTask = newNode; 
} 
var tasks = new WorkflowTaskLinkedList(); 
tasks.insert({name:"C",id:"http://456"}, {name:"head"}); 
console.log(tasks.find({name:"C"}))
console.log(JSON.stringify(tasks.head))