I know how to write to an XML file with c# but I am having an issue with it just overwritting what is already in the file. For example:

Say I have this in my "Database" already

<?xml version="1.0"?>
<Inventory>
<Product>
<ItemNumber>aaa</ItemNumber>
<Title>aaa</Title>
<Description>aaa</Description>
<Cost>aaa</Cost>
<Tax>aaa</Tax>
<TCost>aaa</TCost>
<Quantity>aaa</Quantity>
<PurchaseDate>aaa</PurchaseDate>
</Product>
</Inventory>

Now I want to add another product (bbb) to the inventory. As of right now, It just overwrites whats already in the xml file so the file would only have product bbb not product aaa. This is want I want.

<?xml version="1.0"?>
<Inventory>
<Product>
<ItemNumber>aaa</ItemNumber>
<Title>aaa</Title>
<Description>aaa</Description>
<Cost>aaa</Cost>
<Tax>aaa</Tax>
<TCost>aaa</TCost>
<Quantity>aaa</Quantity>
<PurchaseDate>aaa</PurchaseDate>
</Product>
<Product>
<ItemNumber>bbb</ItemNumber>
<Title>bbb</Title>
<Description>bbb</Description>
<Cost>bbb</Cost>
<Tax>bbb</Tax>
<TCost>bbb</TCost>
<Quantity>bbb</Quantity>
<PurchaseDate>bbb</PurchaseDate>
</Product>
</Inventory>

Anyone have a little example that will accomplish this task?