System.InvalidCastException: Object cannot be cast from DBNull to other types. at System.DBNull.System.IConvertible.ToInt32(IFormatProvider provider) at System.Convert.ToInt32(Object value) at BUSINESSLAYER.Venue.GetVenueIDByNameCity(String venue_name, String city_name) in F:\Visual Studio 2008\Projects\clubdose (2)\BUSINESSLAYER\Venue.cs:line 274