T-SQL Composite Index Query
===

I'm using sql server 2008

Lets say i have the following table--

Orders
======
* OrderID
* CustomerID
* StatusID
* DateCreated

and i have the following queries--

`select CustomerID from Orders where OrderID = 100`

`select OrderID from Orders where CustomerID = 20`

`select OrderID, StatusID from Orders where CustomerID = 100 and OrderID = 1000`

If i make the following index--

`create nonclustered index Example
  On dbo.Orders(OrderID,CustomerID)
  Include(StatusID)`

Does that take care of optimization of all 3 queries with one index? In other words, do composite indexes improve queries that use one of the items within the composite? Or should individual indexes be created just on those columns as well (ie OrderID, CustomerID) in order to satisfy queries 1 and 2?
