How to generate bill numbers dynamically....

Random randnum = new Random();

1.int num = randnum.Next();

2.int num = random.Next(100);

It generate a positive number up to 100 including 0.

3.int num = random.Next(1, 100);

It generates a number between 1 and 100.

For more information check below link.

http://www.c-sharpcorner.com/UploadFile/mahesh/RandomNumber11232005010428AM/RandomNumber.aspx

Hope this will help you.

Thanks.