Dataset Update

[C# Programming]

Hi,
this is my last chance to understand how to update a database through a dataset.
My application is here : [1].
I did a simple application to understand the databases and relative classes in C#.
I have seen that VS2008 is not setting the updatecommand in the wizard, so I fill in by hand. Maybe the problem is there.

UPDATE Customers
SET LastName = @LastName, FirstName = @FirstName
WHERE (CustomerID = @CustomerID)


Thanks in advance.
Stefano

[1] http://www.mediafire.com/?3zgfdmzgnyg