WAP to convert the string from lower case to upper case?

 WAP to convert the string from lower case to upper case?  
 #include <stdio.h>  
 #define MAX_SIZE 100 //Maximum size of the string  
 int main()  
 {  
   char string[MAX_SIZE];  
   int i;  
   printf("Enter your text : ");  
   gets(string);  
   for(i=0; string[i]!='\0'; i++)  
   {  
     if(string[i]>='a' && string[i]<='z')  
     {  
       string[i] = string[i]-32;  
     }  
   }  
   printf("Uppercase string : %s\n",string);  
   return 0;  
 }