The defense in the case against former [tag]Enron[/tag] president [tag]Jeffrey Skilling[/tag] and former Enron chairman [tag]Kenneth Lay[/tag] is claiming that there was no wrongdoing at the company. In day one of the defense case, testimony by five former Enron employees was meant to refute the government’s accusations that Skilling and Lay mischaracterized the performance to the retail energy services unit. Skilling might testify as early as Tuesday.