How to generate a verification code(mixed of char and int)?

private string genrandom(int count)



{



string var ="A-Z,0-9";

// for the above code use A to z characters and 0 to 9 nos



string[] verifycode = var.Split(',');



int t=-1;

// temp varaiable

string finalcode =string.Empty;



Random rand = new Random();



for (int i = 0; i < count; i++)

{ 

if t!= -1)

{ 

rand = new Random(i * t* ((int)DateTime.Now.Ticks));

}

int t1 = rand.Next(36);

if t!= -1 && temp == 1

{ 

return genrandom(count);

}

t= t1;

finalcode += verifycode [t1];

}

return finalcode; 

}