Query SQL Server Table

I have created a connection to a SQL Server database as follows:








Dim user As String = Request.Form("txtUserName")


Dim Pwd As String = Request.Form("txtPassword")





Dim connectionString As String = "data source=INDUS;initial catalog=101032844;Integrated Security=SSPI"


Dim commandString As String = "select user_id, password from logon"


Dim dataAdapter As New System.Data.SqlClient.SqlDataAdapter(commandString, connectionString)


Dim dataSet As New DataSet()


dataAdapter.Fill(dataSet)


Dim dataTable As DataTable = dataSet.Tables(0)








What I want to do now is check the value the user enters into a textbox against the values in the table.


E.g





Check if txtuser.Text = a user_id in table logon


and that txtpassword.Text= a password in table logon


and that they correspond to same record.





How do I go about this?