A Small Javascript task

Design a system that models the way the client browser maintains the aforementioned state. The system must allow the user to enter a new URL into the system and either go back to a URL loaded previous to the current URL or go forward to a URL loaded after the current URL. The storage mechanism used by the browser must include two stacks (one backward and one forward) both of which support the following behaviour: ? LIFO ? Pop item from stack ? Push item onto stack ? Empty a stack Generally speaking, the backward stack stores items of previously visited URLs and the forward stack stores items moved from the backward stack to the forward stack. Specific requirements: The system must allow the user to interact in three ways: enter a new URL, recover URLs from the backward stack; and recover URLs from the forward stack. The actions of the user should produce the following results: ? Entering URL (via an address bar) o Push current document onto backward stack o Empty forward stack ? Recover URL from backward stack o Push current document onto forward stack o Pop backward stack o Load popped URL as current document ? Load URL from forward stack o Push current document onto back stack o Pop forward stack o Load popped URL as current document ? Additional Rules o The system is initialised with a Home page o A new Window has empty stacks o Popping an Empty Stack is non-fatal Implementation Implement a client interface to support the requirements and demonstrate the principles in full. The best approach to take in order to solve the problem is to use an event based style of programming. Use appropriate form components to represent the components of the browser and a series of JavaScript functions to model the behaviour of the browser. The design must simulate the behaviour of the web client, but not duplicate its performance. Do not, therefore, write code which calls a web page via a URL and inserts the page into part of the loaded document. Additional Requirements Explore regular expressions implementations should support a full URL string and are able to extract the relevant parts and store/display them appropriately. You should also explore stacks in more detail, implementations must support the data structures made from objects (nodes and links) in the form of linked lists. These structures do not allow non-sequential access to data.