Random numbers in C#

Question

I get the error below when I try to run the application I am sure its something simple but I dont see it. What I am trying to do it when I click a button I have labeled Play. I

Answer 1

Setup one Random object and initialize it once.

class Form1
{
    ...
    Random rnd = new Random();
}

then to use it every time it is needed

void RandomNumber(int min, int max)
{
    int num = rnd.Next(min, max);
    ...
}

What happens everytime you call new() it re-seeds the random number and you may end up with the same numbers over and over. I have had this happend to me and it killed me