title: XmlSerializer.Serialize Stripping the <xml> tag
body: <p>I am trying to get communicate to a payment processor. When I use <code>XmlSerializer.Serialize</code> 
  on my object I get </p>
  
  <pre><code>&lt;?xml version=\"1.0\" encoding=\"utf-16\"?&gt;
  &lt;txn xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\"&gt;
    &lt;ssl_merchant_id&gt;xxxxxx&lt;/ssl_merchant_id&gt;
    &lt;ssl_user_id&gt;xxxxxx&lt;/ssl_user_id&gt;
    &lt;ssl_pin&gt;xxxxxx&lt;/ssl_pin&gt;
    &lt;ssl_test_mode&gt;True&lt;/ssl_test_mode&gt;
    &lt;ssl_transaction_type&gt;ccavsonly&lt;/ssl_transaction_type&gt;
    &lt;ssl_card_number&gt;4111111111111111&lt;/ssl_card_number&gt;
    &lt;ssl_exp_date&gt;0612&lt;/ssl_exp_date&gt;
    &lt;ssl_avs_address&gt;101 Main St.&lt;/ssl_avs_address&gt;
    &lt;ssl_avs_zip&gt;90210&lt;/ssl_avs_zip&gt;
  &lt;/txn&gt;
  </code></pre>
  
  <p>Prior to using that method, I manually built the XML for testing and this worked:</p>
  
  <pre><code>&lt;txn&gt;
    &lt;ssl_merchant_id&gt;xxxxxx&lt;/ssl_merchant_id&gt;
    &lt;ssl_user_id&gt;xxxxxx&lt;/ssl_user_id&gt;
    &lt;ssl_pin&gt;xxxxxx&lt;/ssl_pin&gt;
    &lt;ssl_test_mode&gt;True&lt;/ssl_test_mode&gt;
    &lt;ssl_transaction_type&gt;ccavsonly&lt;/ssl_transaction_type&gt;
    &lt;ssl_card_number&gt;4111111111111111&lt;/ssl_card_number&gt;
    &lt;ssl_exp_date&gt;0612&lt;/ssl_exp_date&gt;
    &lt;ssl_avs_address&gt;101 Main St.&lt;/ssl_avs_address&gt;
    &lt;ssl_avs_zip&gt;90210&lt;/ssl_avs_zip&gt;
  &lt;/txn&gt;
  </code></pre>
  
  <p>How would I go about stripping out the <code>&lt;?xml version=\"1.0\" encoding=\"utf-16\"?&gt;</code> and <code>xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\"&gt;</code> from the XML or not have the serializer generate it to begin with?</p>
  
  <p>My object looks like:</p>
  
  <pre><code>[XmlRoot(ElementName="txn")]
  public class AvsTransmission
  {
      [XmlElement]
      public string ssl_merchant_id { get; set; }
      [XmlElement]
      public string ssl_user_id { get; set; }
      [XmlElement]
      public string ssl_pin { get; set; }
      [XmlElement]
      public string ssl_test_mode { get; set; }
      [XmlElement]
      public string ssl_transaction_type { get; set; }
      [XmlElement]
      public string ssl_card_number { get; set; }
      [XmlElement]
      public string ssl_exp_date { get; set; }
      [XmlElement]
      public string ssl_avs_address { get; set; }
      [XmlElement]
      public string ssl_avs_zip { get; set; }
  }
  </code></pre>