while(test)
        {
            if (req == 1 || req == 2 || req == 3)
            {
                nTimes = dialog.readInt("Times to reproduce the effect in animation: ");
            }
            switch (req)
            {

                case 0:
                System.exit(0);
                test = false;
                break;
                case 1:
                //nTimes = dialog.readInt("Times to reproduce the effect in animation: ");
                this.drawReq1(nTimes);
                this.removeAll();
                break;
                case 2:
                this.drawReq2(nTimes);
                this.removeAll();
                break;
                case 3:
                this.drawReq3(nTimes);
                this.removeAll();
                break;
                case 4:
                this.drawReq4();
                this.removeAll();
                break;
            }

            //Bubbles b = new Bubbles(150, false);
            //RandomGenerator r = new RandomGenerator();
        }