My instance cant move down past a wall array, so confused!

[jakeglover1210]

My instance variable (esk) can not move down past where the wall array ends on the bottom. The top works fine! I don't know what's wrong here, hes colliding with nothing beside this wall all the way to the middle of the level.

private function onEnter( e:Event )
		{
			
			checkCollisions();
		}
			private function checkCollisions()
		{
			var leftSideWall:int;
			var rightSideWall:int;
			var topSideWall:int;
			var bottomSideWall:int;
			
			var leftRightBuffer:int = 2;
			var topBottomBuffer:int = 2;
			
			var leftSideesk:int   = esk.x - esk.width/2;
			var rightSideesk:int  = esk.x + esk.width/2;
			var topSideesk:int    = esk.y;
			var bottomSideesk:int = esk.y;
			
			for( var i:int = 0; i < walls.length; i++ )
			{
				leftSideWall   = walls[i].x - walls[i].width/2;
				rightSideWall  = walls[i].x + walls[i].width/2;
				topSideWall    = walls[i].y - walls[i].height/2;
				bottomSideWall = walls[i].y + walls[i].height/2;
				
					
					if( ( rightSideesk >= leftSideWall ) && ( leftSideesk <= rightSideWall ) )
				{
					
					if( ( bottomSideesk <= topSideWall ) && ( bottomSideesk + esk.dy >= topSideWall) )
					{
						trace("hittop");
						esk.y = topSideWall - topBottombuffer;
						esk.HITTOP = true;
						break;
					}
					
					else if( ( topSideesk >= bottomSideWall ) && (topSideesk - esk.dy >= bottomSideWall ) )
					{
						trace("hitbot");
						esk.y = bottomSideWall + esk.height/2  + topBottombuffer;
						esk.HITBOTTOM = true;
						break;
					}
				}
				else
				{
					esk.HITTOP = false;
					esk.HITBOTTOM = false;