Random Numbers

.NET has a Random class
The Next function has a parameter that allows you to specify a range of integers you want returned.

System.Random rnd = new System.Random(); 
int month  = rnd.Next(1, 100);  // creates a number between 1 and 100 

Passing in 10 returns numbers from 0 to 9.

System.Random rnd = new System.Random(); 
int number  = rnd.Next(10); 

Not passing in a value returns numbers from 0 to 1.

System.Random rnd = new System.Random(); 
double number  = rnd.NextDouble();