Program to Convert small letter to capital letter

Program to Convert small letter to capital letter
#include<stdio.h>
#include<conio.h>
main()
{
char s[100];
int i;
printf("\nEnter a string : ");
gets(s);

for (i = 0; s[i]!='\0'; i++)
{
if(s[i] >= 'a' && s[i] <= 'z')
{
s[i] = s[i] - 32;
}
}
printf("\nString in Upper Case = %s", s);
getch();
}
Output

              Enter the string : f

              String in Upper Case = F