Commandtext problem

I am trying to get the return value from the select statement and store it into a variable
does anyone know whats wrong with my code?

Private Function check_login(ByVal login As String) As String

dim dbCon As SqlConnection = New SqlConnection
Dim dbCmd As SqlCommand = New SqlCommand

Dim returnuser As Integer

dbCon.ConnectionString = _
"Data Source=localhost;" + _
"Initial Catalog=registeruser;" + _
"User ID=int422;" + _
"Password=int422"

dbCon.Open()

dbCmd.Connection = dbCon
dbCmd.CommandText = "SELECT count(login_id) from users where login_id=@.login"
dbCmd.CommandType = CommandType.Text

returnuser = dbCmd.ExecuteScalar

Return returnuser

dbCon.Close()

SELECT count(login_id) from users where login_id=@.login

I don't see where you are setting the value for the @.login parameter. Also the dbCon.Close() should be immediately after the ExecuteScalar() call and, in particular, before the return statement.