Dual Employment

Hi all, Is dual Employment is legal in India?? I have checked all websites n searched that Dual Employment is not legal in India, But question is 1. if some one is working at two places & first employer came to know about it ?? What would the action against the employee. 2. After one the employer knows abt dual Employment of employee n employee resignes from second Organization then what action the first employer will take against the employee.. Pls help me to know this matter