itch.io

Something like this:

var namp;
namp = amp_get_new_party_id()
if(namp != NONE){
     //Fits in party
     amp_generate_monster(namp, SPECIES, LEVEL)
}
else{
     namp = amp_get_new_box_id()
     if(namp != NONE){
         //Placed in box
         amp_generate_monster(namp, SPECIES, LEVEL)
     }
     else{
         //No room, can't be taken
     }
}