SkinMgr.evalCustomSkin (param, creator)
create a custom skin

Sourcecode in SkinMgr/objectFunctions.js:
1:   function evalCustomSkin(param, creator) {
2:      if (!param.prototype)
3:         throw new Exception("skinCustomPrototypeMissing");
4:      else if (!param.name)
5:         throw new Exception("skinCustomNameMissing");
6:      else if (this[param.prototype] && this[param.prototype][param.name])
7:         throw new Exception("skinCustomExisting");
8:      else if (this.getOriginalSkin(param.prototype, param.name))
9:         throw new Exception("skinCustomExisting");
10:     else if (app.skinfiles[param.prototype] && app.skinfiles[param.prototype][param.name])
11:        throw new Exception("skinCustomExisting");
12:     var s = new Skin(this._parent, param.prototype, param.name, creator);
13:     s.custom = 1;
14:     if (!this.add(s))
15:        throw new Exception("skinCustomCreate");
16:     return new Message("skinCustomCreate", [param.prototype, param.name]);
17:  }