AJAX :: Broadcast New Data Using Webservice?

I am working on an application just like any fast food restaurant uses for example McDonalds.

Basically, application consists of three parts.

1) Web Application # 1 to take orders (Used by the clerk(s))

2) Web Application # 2 to process orders (used by the chef back in the kitchen)

3) WebService returns new orders (with PENDING status) to Web Application # 2.

Write now, Application # 1 adds new orders to the database. Application # 2 calls the WebService to get new ordes by REFRESSHING the page again and again. Refreshing the page over and over again is the problem.

I want the WebService to automatically send new data (oredrs with PENDING status) to Web Application # 2 whenever Application #1 add new order.

Application # 1 can call WebService (sending true flag) to let it konw that something has been added so the WebService can broadcast new date to Application # 2

Here is the flow which I am trying to achieve

Application # 1 (Takes new Order)
Application # 1 then call WebService (sending true)

WebService (if true is received), send new data to WebApplication # 2, cause postback on Applicatin # 2 automatically

For Example just imagine when you walk in McDonalds

Clerk takes your order -> New order is automatically send to the Kitchen (to process order)

Here is the breakdown

Application # 1 = Clerk taking order
WebService = Mechanism which is sending new order to Kitchen
Application # 2 = Monitor in the Kitchen receiving orders.