Question: Clearing the Bridge

[drcroc]

So I shoot down the hornet's nest and get the soldiers clear of the bridge, run to the other side, and then drop down to the lower ledge to collect the M16.  Problem is, the controls confuse me, it's a metal gear game but x and o aren't reversed.  Up is down, monday is tuesday, and snake keeps falling into the pit to his death.  What button do I press to make him grab that lower ledge while he's in midair???