Errm, well, assuming that you are using v. 2.1 and not 1.1, you really don't need to call the Game_Quest methods directly like that. I created a number of methods directly in Game_Interpreter to help fix that issue.
All you would need to do is use the following code:
complete_objective(122, 0)
All of the methods that are available to you are quoted in the first post:
Instructions
Paste this script into the Script Editor (F11) in its own slot above Main and below Materials.
I would recommend separating the Configuration module from the Script itself in two different slots, as I think it makes it neater. That is totally optional though. If you do want to do it though, instructions on where to make the split are located in the Script Header at line 20.
Instructions for creating, updating and monitoring quests, as well as for changing the settings, are all in the Script header and in the two EDITABLE REGIONS. It is highly recommended that you take the time to familiarize yourself with them in detail.
In brief, however, the following codes are used to update quest progress:
reveal_objective (quest_id, objective_id_1, ..., objective_id_n)
quest_id : the integer ID of the quest you want to access.
objective_id_1, ..., objective_id_n : a list of the IDs of the
objectives you want to operate on. It can be as few as one or as
many as all of them.
conceal_objective (quest_id, objective_id_1, ..., objective_id_n)
complete_objective (quest_id, objective_id_1, ..., objective_id_n)
uncomplete_objective (quest_id, objective_id_1, ..., objective_id_n)
fail_objective (quest_id, objective_id_1, ..., objective_id_n)
unfail_objective (quest_id, objective_id_1, ..., objective_id_n)
change_reward_status (quest_id, value)
The following codes are used in a conditional progress to monitor quest progress (each of the objective_etc? will only return as true if the quest is also revealed):
quest_revealed? (quest_id)
quest_id : the integer ID of the quest you want to access.
objective_revealed? (quest_id, objective_id_1, ... objective_id_n)
objective_id_1, ..., objective_id_n : a list of the IDs of the
objectives you want to operate on. It can be as few as one or as
many as all of them.
quest_complete? (quest_id)
objective_complete? (quest_id, objective_id_1, ... objective_id_n)
quest_failed? (quest_id)
objective_failed? (quest_id, objective_id_1, ... objective_id_n)
quest_rewarded? (quest_id)
For details on what each of these does, see the script. As well, there are lots of other instructions in the script you should pay attention to. Read them carefully!
You can also change the attributes of quests in-game with any of the following codes:
quest (quest_id).method = new_value
method : the attribute you want to change. This can be either:
banner; name; description; objectives; prime_objectives; rewards;
common_event_id; icon_index; or custom_categories.
new_value : this is the value that you are changing it to. It must
be of the same form as the original (ie. a string for name or
description, an array of strings for objectives, an integer for
icon_index, etc...)
If you are still using 1.1, then I recommend you switch to 2.1, but if you are unwilling to do that, then please see the section on Call Script Errors in my
Script Troubleshooting for the Non-Scripter tutorial. It has tips for breaking up the code into local variables in order to have the operative portion fit on one line.