What was found
DURING PREFLIGHT, BOTH CAPTAIN'S AND FIRST OFFICER'S SLIDING WINDOWS LOCKING MECHANISM LOCATED ON THE TOP FORWARD PART OF THE WINDOW, INTERMITTENTLY WILL NOT RELEASE. THIS RESULTING IN THE WINDOW NOT OPENING. ADJUSTED CAPTAIN'S AND FIRST OFFICER'S SLIDING WINDOWS IAW DC-9 MM 56-10. OPS CHECKED GOOD.