What I need to do is write a program that makes the first character (which is charAt(0) )and the second character (which is charAt(1) ) to become a value that not exceeding 90 which is (0 ~ 90) , but I also have to define them as an independent digit , because my program will make it to invalid if it is other than a digit. 

So for an example it will become invalid if I type in 91
and it will valid if I type in number between 0~90

but I have no idea how to do this...

```
  if(Character.isDigit(loop1.charAt(0))&&  
     Character.isDigit(loop1.charAt(1)))

```

I have tried this ,but not working

```
  if(Character.isDigit(loop1.charAt(0)) &&  
     Character.isDigit(loop1.charAt(1)) && 
      ((loop1 >= 0)&&(loop1 <= 90)))

```

also this one but this is not working( I have no idea what I'm doing)

```
   if(Character.isDigit(loop1.charAt(0)) &&  
      (((int)loop1.charAt(0)) >= 0) && <=9
      Character.isDigit(loop1.charAt(1)) && 
      ((int)loop1.charAt(1)) <= 9)

```

Please help me... thanks a million !