API SetLootMethod

Set the current loot method.
 SetLootMethod(method [,masterPlayer or threshold]) 
=Arguments=
"method" may be any one of the following self-explanatory and case insensitive arguments: "group", "freeforall", "master", "needbeforegreed", "roundrobin".
Additionally, if method is "master", the second argument must be a player name, followed by the optional third argument. The third argument is set to 1 if you're promoting a new master looter, as in the case where you right click on a raid member and select "Promote to Master Looter".
To change the loot threshold, use SetLootThreshold
=Example=
 /script SetLootMethod("master", "name");
Result
If you are the party or raid leader, the script will set the loot method to Master Looter, promote the named char to loot master and report its new status.