A 50 year old lady presented with history of pain upper abdomen, nausea, and decreased appetite for 5 days. She had undergone cholecystectomy 2 years back- Her bilirubin was 10 mg/dl, SGOT 900 lU/L SGPT 700 lU/L and scrum alkaline phosphatase was 280 lU/L. What is the most likely diagnosis