you can write the Global.asax.
vb
Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)Application.Contents("conn") = ("Data Source=IP;Initial Catalog=DataBaseName;uid=username;pwd=password")
or
Application.Contents("conn") = ("Data Source=Your instance name;Initial Catalog=database name;Integrated security=true")
End Sub
and you can write forms button1.Click
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim con As New SqlClient.SqlConnection
con = New SqlClient.SqlConnection(Application("conn"))
con.Open()
......
......
con.close()
end sub