DataSet - Should be easy but I dont know how

I am working on a WebMatrix ASP project. I have a query that returns a System.Data.DataSet but I don't know how to assign the DataSet to a variable so that I can run some validation tests on it.

This is what I have so far...What I want to do is assign the dataset to a variable and to see if it is NULL or Not. I don't how? Any help would be awesome.

Sub Button1_Click(sender As Object, e As EventArgs)
?? = MyQueryMethod(txtPhone.Text)

Thanks,
Matt

Dim oDataSet as System.Data.DataSet = MyQueryMethod(txtPhone.Text)
If oDataSet = Nothing Then
 ' your dataset is jacked up
Else
 ' You got a dataset to work with
End If
' Release memory allocations to the variable.
oDataSet.Dispose()

|||Simply amazing! It's so easy once someone tells you how it is. Worked like a charm...Now I'm all jacked up!!!

Much Respect!!!!

Thanks,
Matt|||Well actually, it didn't quite do as I expected but I'm close. When I execute this code, I am expecting the dataset to have no records or one record, but either way the DataSet is never nothing (at least from my testing).

Maybe I'm just going about my problem the wrong way. I am trying to validate phone number so that I don't have someone enter a duplicate key in my database. So I run an SQL select statement that returns a dataset. The dataset should have one phone number or no phone number and this is how I'm trying to ward off any duplicate keys.

Is there an easier way to prevent a duplicate key entry? Sorry, I'm new at this stuff!!|||You can code as

If oDataSet.Tables(0).Rows.Count = 0 Then
 ' your have no records
Else
 'Response.Write(oDataSet.Tables(0).Rows(0)(0).ToString())
End If

HTH|||Perfect...thanks.