Set custom box button (SSTI API Example)

// Server API
// Commands:
integer SSTI_SERV_API_CUSTOM_BUTTON=-45050001;
integer SSTI_SERV_API_GET_GROUP=-45050002;
integer SSTI_SERV_API_GET_CLOUD=-45050003;
integer SSTI_SERV_API_BOX_CUSTOM_BUTTON=-45050004;
integer SSTI_SERV_API_GET_PARAM=-45050005;
integer SSTI_SERV_API_CUSTOM_HTTP_BUTTONS=-45050006;
integer SSTI_SERV_API_HTTP_REPLY=-45050007;
 
// Events:
integer SSTI_SERV_EVENT_INITIALIZED=-45060001;
integer SSTI_SERV_EVENT_CUSTOM_BUTTON=-45060002;
integer SSTI_SERV_EVENT_GROUP=-45060003;
integer SSTI_SERV_EVENT_CLOUD=-45060004;
integer SSTI_SERV_EVENT_BOX_CUSTOM_BUTTON=-45060005;
integer SSTI_SERV_EVENT_PARAM=-45060006;
integer SSTI_SERV_EVENT_RESET=-45060007;
integer SSTI_SERV_EVENT_LOCALURL=-45060008;
integer SSTI_SERV_EVENT_HTTPBUTTON=-45060009;
integer SSTI_SERV_EVENT_TENANT=-45060010;
integer SSTI_SERV_EVENT_NEW_GUESTPARTNER=-45060011;
integer SSTI_SERV_EVENT_GUESTPARTNER_REMOVED=-45060012;

//
// Set the menu button
setSSTIButton() {
    llMessageLinked(LINK_SET, SSTI_SERV_API_BOX_CUSTOM_BUTTON, "Custom!", NULL_KEY);
    llOwnerSay("SSTI button set");
}
 
default {
    state_entry() {
        // Set the menu button when this script restarts
        setSSTIButton();
    }
 
    link_message(integer sender, integer cmd, string str, key id) {
        if(cmd == SSTI_SERV_EVENT_INITIALIZED) {
            // Also catch the server initialization and re-set the menu
            setSSTIButton();
        }
 
        if(cmd == SSTI_SERV_EVENT_BOX_CUSTOM_BUTTON) {
            llOwnerSay("Tenant " + (string)id + 
                " has pressed the menu button: " + str);
        }
    }
}