llSensor failing on first call

Hi all, haven't played with the sensors much before now, and am just trying to understand why its not working as I think it should. Using the test below as an example, whenever I first touch the object, it returns a blank key on the first attempt, but provides a correct response on every press afterwards.

Assistance and illumination is always appreciated -)

Dominus

key myid;
default
{
state_entry()
{
llSay(0, "Hello, Avatar!";
}

touch_start(integer total_number)
{
string name = "Dominus Skye";
llSensor(name,NULL_KEY,AGENT,99,PI);
llSay(0,"your key is: "+(string)myid);
}
sensor(integer who)
{
myid = llDetectedKey(0);
}
}

Sample output based on 4 touches:
Object: Hello, Avatar!
Object: your key is:
Object: your key is: xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx
Object: your key is: xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx
Object: your key is: xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx

(Actual key changed to protect the guilty lol)

it's because it's not getting the key. LSL doesn't work that way, put that llSay(0,"your key is: "+(string)myid); AFTER the uuid = llDetectedKey(0); in the sensor event.

Events in the same script don't execute simultaneously, so the sensor() event isn't going to begin until the touch_start() event ends.

This should work.

default {
  touch_start(integer total_number) {
    llSensor("Dominus Skye", NULL_KEY, AGENT, 96, PI);
  }

  sensor(integer num_detected) {
    key myid = llDetectedKey(0);
    llSay(0,"your key is: "+(string)myid);
  }
} 

Also, the sensors are limited to 96m not 99m....and are you sure you need to scan that far?

Thanks all,

Handling the coding within the body of the sensor event does work - and I am seeing that the call doesn't execute until the calling function terminates, so all these answers have been beneficial. I'll adapt my code to suit. =)

As far as the distance of the scan, well, I probably don't need to use the maximum distance, I guess there's additional server-side lag generated the greater the scanning distance?

Cheers,
Dominus

A bit yea, you should only have to worry if you are using llSensorRepeat set to a high rate of fire.....but might as well be efficient in small scripts too.

If you just need one key, you can use llDetectedKey(0) in the touch_start event. If you are wanting to get all of those around the object you may want to set the name value in llSensor to null and use this:

    sensor(integer total_number) {
        llWhisper(0, (string)total_number + " avatars detected");
        integer i;
        for (i = 0; i < total_number; i++) {
            llWhisper( 0, llDetectedName(i) + ": " + (string)llDetectedKey(i));
        }
    }