Detecting av within area of polygon

// Create 2 prims and color one red and the other green. The red prim is the NORTH_EAST_CORNER and should be positioned in the NORTH_EAST_CORNER on the "roof" or "ceiling" of the area you want to scan. The green prim is the SOUTH_WEST_CORNER and should be positioned in the SOUTH_WEST_CORNER on the "floor" of the area you want to scan.

vector NORTH_EAST_CORNER=<223.95860, 29.33944, 2706.80542>;

vector SOUTH_WEST_CORNER=<208.70197, 14.07825, 2700.38452>;



default
{
    state_entry()
    {
        llSetTimerEvent(1.0);
    }

    timer()
    {
        llSetTimerEvent(0.0);

        list keys=llGetAgentList(AGENT_LIST_PARCEL,[]);
 integer total=llGetListLength(keys);
 integer idx = 0;

  for(idx=0;idx<total;++idx)
    {
        key av=llList2Key(keys,idx);
        list params=llGetObjectDetails(av,[
                OBJECT_POS
            ]);
        vector AvPos=(vector)llList2String(params,0);

    if
    (AvPos.x > SOUTH_WEST_CORNER.x & AvPos.x < NORTH_EAST_CORNER.x & AvPos.y > SOUTH_WEST_CORNER.y & AvPos.y < NORTH_EAST_CORNER.y & AvPos.z > SOUTH_WEST_CORNER.z & AvPos.z < NORTH_EAST_CORNER.z)
     {
     llOwnerSay(llKey2Name(av) + " has entered the area");
     }
        }


        llSetTimerEvent(1.0);
    }
}