def initialize_ad(ad_hash)
				ad = BingAdsApi::Ad.new(ad_hash)
				case ad_hash["@i:type".to_sym]
				when "TextAd"
					ad = BingAdsApi::TextAd.new(ad_hash)
				when "MobileAd"
					ad = BingAdsApi::MobileAd.new(ad_hash)
				when "ProductAd"
					ad = BingAdsApi::ProductAd.new(ad_hash)
				end
				return ad
			end
def initialize_ad(ad_hash)
				ad = BingAdsApi::Ad.new(ad_hash)
				case ad_hash["@i:type".to_sym]
				when "TextAd"
					ad = BingAdsApi::TextAd.new(ad_hash)
				when "MobileAd"
					ad = BingAdsApi::MobileAd.new(ad_hash)
				when "ProductAd"
					ad = BingAdsApi::ProductAd.new(ad_hash)
				end
				return ad
			end
Private : Returns an instance of any of the subclases of BingAdsApi::Ad based on the '@i:type' value in the hash

 Author:: jlopezn@neonline.cl

 ad_hash - Hash returned by the SOAP request with the Ad attributes

 Examples
   initialize_ad({:device_preference=>"0", :editorial_status=>"Active",
      :forward_compatibility_map=>{:"@xmlns:a"=>"http://schemas.datacontract.org/2004/07/System.Collections.Generic"},
      :id=>"1", :status=>"Active", :type=>"Text",
      :destination_url=>"www.some-url.com", :display_url=>"http://www.some-url.com",
      :text=>"My Page", :title=>"My Page",
      :"@i:type"=>"TextAd"})
   # => BingAdsApi::TextAd

 Returns:: BingAdsApi::Ad subclass instance