**Hi! Why is my code not suitable?**

**Your code so far**

```
var stringArr = str.split(' ');
var temp = '';
for(i = 0; i < stringArr.length; i++){
for(j = 0; j < stringArr[i].length; j++){
if(stringArr[i][j].charCodeAt() == 46 || stringArr[i][j].charCodeAt() == 33 || stringArr[i][j].charCodeAt() == 63){
temp += stringArr[i][j];
} else if(stringArr[i][j].charCodeAt() >= 65 && stringArr[i][j].charCodeAt() <= 77){
temp += String.fromCharCode(stringArr[i][j].charCodeAt()+13);
} else {
temp += String.fromCharCode(stringArr[i][j].charCodeAt()-13);
}
}
temp += ' ';
}
return temp;
}
// Change the inputs below to test
rot13("SERR YBIR?");
```