def escape(txt)
			@@html_entities.inject(txt.to_s.dup) { |str, map| 
				char, entity = map
				str.gsub!(char, '&' << entity << ';')
				str
			}
		end
def escape(txt)
			@@html_entities.inject(txt.to_s.dup) { |str, map| 
				char, entity = map
				str.gsub!(char, '&' << entity << ';')
				str
			}
		end
escape '&', '<' and '>' characters in txt