the investigators will compare the effect of pre-operative oblique subcostal TAP and lateral TAP blocks on the total perioperative opioids consumption for patients undergoing elective laparoscopic cholecystectomy

General anesthesia induction will be achieved using a sleeping dose of fentanyl 1µg/kg intravascular(IV), propofol 2mg/kg (IV), and atracurium 0.5mg/kg (IV) to facilitate tracheal intubation. General anesthesia will be maintained with lungs ventilation by pressure controlled mode with isoflurane

During anesthesia maintenance Intraoperatively, if blood pressure BP or heart rate (HR) increase more than 20% from baseline, intravenous morphine (3- 5mg) will be given to stabilize the patients' haemodynamics. Fifteen minutes before the end of surgery all patients will receive 1g intravenous paracetamol and 4 grams ondansetron.

Patients will be randomly divided into three equal groups:

Group A: will receive bilateral oblique subcostal TAP block Group B: will receive bilateral lateral TAP block. Group C :will receive postoperative morphine by patient-controlled analgesia (PCA).

Inclusion Criteria:

• Eligible patients will be older than 21 years old with American society of anaesthesia physical status I& II scheduled for elective laparoscopic cholecystectomy.

Exclusion Criteria:

• - Uncooperative.
• Patients who have allergy to any of the study drugs.
• Patients who are on opioids.
• Known abuse of alcohol or medication.
• Local infection at the site of injection or systemic infection.
• Pregnancy.
• Patients with coagulation disorders or on anticoagulation therapy.