DropDownLists and NULL values

[Nightcrawler]

I have a table adapter that looks like this:

TableAdapter.GetData(string name, string email, ing countryid, int
stateId)

This is calling the following stored procedure

SELECT *
FROM Table
WHERE Name= COALESCE(@Name,Name)
AND Email = COALESCE(@Email,Email)
AND CountryId = COALESCE(@CountryId,CountryId)
AND StateId = COALESCE(@StateId,StateId)

The name and email are textbox controls and the country and state are
dropdownlists. The end user selects any combination of these as hits a
search button.

The problem is that I want the ability to pass a NULL value into the
stored procedure. So if the user does not select anything in the
dropdowns, I need to pass in NULL values for this to work. Is there an
easy way to do this?

Thanks