// Take into account exceptions might occur
try
{
  // some code here that's less funny ;-)
}
// Process exceptions
catch (Exception ex)
{
}

//doesn't close connection
var tags = String.Join(",", criteria.Tags.Select(t => t.SID.ToString()).ToArray());
cmd.Parameters.Add(new SqlParameter("@tags", tags));
 
//doesn't close connection
var parm = new SqlParameter("@tags", String.Join(",", criteria.Tags.Select(t => t.SID.ToString()).ToArray()));
cmd.Parameters.Add(parm);
 
//CLOSES THE CONNECTION?!
cmd.Parameters.Add(new SqlParameter("@tags", String.Join(",", criteria.Tags.Select(t => t.SID.ToString()).ToArray())));

public class SomeController
{
  private static SomeController instance;
  public SomeController(){}
 
  /// <summary>
  /// Gets the instance.
  /// </summary>
  /// <returns></returns>
  public static SomeController GetInstance()