how to increment by 1 value in c#

Question

how to increment by 1 value in c# 

int x = 0;

for (int i = 0; i < tStudent.adm_no; ++i)

if (tStudent.adm_no >0)

{

x = x + 1;

tStudent.adm_no = x;

}

i want when i admit new student i got a new adm_no automatically