Problem sa connection string-om

Code:

private string connectionString = @"Server=VLADA-PC\SQLEXPRESS;Database=SMSMessages;user id=sa;password=";

Code:

try
            {
                sqlConnection = new SqlConnection ();
                sqlConnection.ConnectionString = getConnectionString();
                sqlConnection.Open();
            }
            catch (Exception ex)
            {
                throw ex;
            }

Code:

@"Data Source=VLADA-PC\SQLEXPRESS;Initial Catalog=SMSMessages;Integrated Security=True; ";

Code:

SqlConnection Conn = new SqlConnection(SQL_CONNECTION_STRING);

Code:

SqlCommand Conn = new SqlCommand("Select * from Neka_Tabela", SQL_CONNECTION_STRING);