Thread: cant figure it out

i am trying to allow combinations of 3 numbers eg. 222 or 2 numbers followed by a capital letter eg. 21A. It works fine for the 3 numbers but doesnt accept 2 numbers followed by a letter.

Code:

 if((u_no[0] > 47) && (u_no[0] < 58))
 {
    if((u_no[1] > 47) && (u_no[1] < 58))
    {
       if((u_no[2] > 47) && (u_no[2] < 58))
       {
          u_count_parts++;
          printf("u_no ok\n");
       }
       if((u_no[2] > 64) && (u_no[2] > 91))
       {
          u_count_parts++;
          printf("u_no ok\n");
       }
    }
 }