S. 151 : Reassessment-Sanction for issue of notice-After the expiry of four years-Valid sanction-Sanction received from JCIT instead of PCIT/CCIT/CIT-Law in force on the date of issue of notice is applicable-Reassessment notice is valid-Source of deposit not substantiated-Addition as cash credit affirmed. [S. 68, 148, 151(2)]