/*this.name        = "ups_courier"; 
this.author      = "eric walch"; 
this.copyright   = " 2008 the Oolite team."; 
this.description = "Missions of UPS Courier"; 
this.version     = "1.3.5"; 
*/

All is working but maybe I do stupid things. As this is the first larger JS OXP for Oolite, a lot of others will use this as example. So I tried to write is clearly. But look at the way missions are offered. It is important that such a method is used that does not clash with missions.
In my first tests with multible offers from two missionlines it worked and they followed each other without pause. But when one is screen is missed no others will follow without using the ticke. For this reason a timer is started in these occasions to get back in control. Version 1.71 Oolite will become a "missionChoiceWasReset" event handler. Than a timer for this purpose can be removed. 

In Oolite 1.70 there is a bug with spawned ships. Only the script of the first ship works, no further. "player." and "mission." are not known anymore. I also had the same problem with added ships. I saw Svengalii made a new function from the eventhandlers and put the "this.version" in comment. His versions worked so I tried it also. Now the added ships work (partially).

Addition: When entering a system for the second time and the ship is than added for the second time, the reference-bug is bypassed with this method. When adding a second ship in the same system the bug is still there. So for some ships I disabled the scripts until version 1.71. For other ships that are very rare I left them in as a second adding in one game is rare.