Queue Class.js

function Queue() {
  this.tail = null;
	this.head = null;
}
Queue.prototype.enqueue = function(n) {
	//this.head = n;
	//n.getNextNode = this.tail;
	if(this.head == null){
		this.head = n;
		return this.head;
	}
	else{
		this.tail = n;
		return this.tail;
	}
}
Queue.prototype.dequeue = function(n) {
	n = this.head;
	if( n != null){
		this.head = null;
		this.tail = n;
	}
	return this.tail;;
}
Queue.prototype.peek = function(n) {
	return this.head;
}
Queue.prototype.getLength = function(n) {
	var counter = 0;
	if(this.head != null){
		counter++;
	}
	return counter;
}

getLength: there is an infinite loop when you only check the head of the Queue. instead, check each specific node with a local variable (call it n).
only enqueue should take a parameter
enqueue does not need to return anything
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