@Planck:
Remember that AND has a greater operator precedence than OR, so what you wrote was actually this:
(this and (player == ws)) || (player == ws1)|| (player == ws2)|| (player == al)|| (player == al1)|| (player == al2)
Which definitely wasn't what you meant (it will trigger whether it is clicked or not, for everyone except ws)!
@Knight Trane:
The problem with doing this with an editor-based trigger is that it will not exactly do what you expect. It works great when you are limiting it to just one person, but once you have more than one (or an radio trigger available to everyone, for that matter), then it probably doesn't work as you'd like, or expect, it to. In ArmA, whenever anyone uses a radio trigger, everyone who could have used it will have their triggers triggered (condition will be true and onAct will be run). You don't even know which one of those players actually used the radio!
The simple answer would be to just limit the trigger to the three people who should have it:
this and (player in [ws, ws1, ws2])
and delete the radio text for the people that should have it using setRadioText (of course, first waiting until they create their player object). But as I explained, the problem of the trigger running on everyone's machine is probably a problem, such as, for example, creating multiple artillery firings when you just wanted one, so best to do something else...
This issue means it is much better to use script-based triggers for the majority of MP missions:
// Run from init.sqf (or init.sqs) with:
// [] execVM "createTrigger.sqf";
// Exit on a dedicated server only.
if (isServer and (isNull player)) exitWith {};
// Wait until the player spawns in, but don't do anything if it is the wrong player.
waitUntil { alive player };
if (not (player in [ws, ws1, ws2])) exitWith {};
_trigger = createTrigger ["EmptyDetector", [0, 0, 0]];
_trigger setTriggerActivation ["ALPHA", "PRESENT", true];
// Er, just run whatever code, script or function you want from the second parameter, of course...
_trigger setTriggerStatements ["this", "nul = [] execVM 'triggerActivated.sqf'", ""];