integer filter;// default is 0

default
{

    touch_start(integer total_number)
    {
        vector start = llGetPos();
        vector ground = start;
        ground.z = llGround( ZERO_VECTOR );
        vector end = <start.x, start.y, ground.z>;

        if ( filter > 8 )
            filter = 0;

        llOwnerSay("Filter " + (string)filter);

        list results = llCastRay(start, end, [RC_REJECT_TYPES, filter, RC_MAX_HITS, 1] );

        integer hitNum = 0;
        // Handle error conditions here by checking llList2Integer(results, -1) >= 0
        while (hitNum < llList2Integer(results, -1))
        {
            // Stride is 2 because we didn't request normals or link numbers
            key uuid = llList2Key(results, 2*hitNum);

            string name = "Land"; // if (uuid == NULL_KEY)
            list pos;

            if (uuid != NULL_KEY)
                name = llKey2Name(uuid);
                pos = llGetObjectDetails(uuid, ([OBJECT_POS]));

            llOwnerSay("Start :" + (string)start + "-" + "End : " + (string)end + " - Hit : " + name + " - Location : " + llList2String(pos,0) + ".");

            ++hitNum;
        }

        ++filter;
        llResetScript();
    }
}