Upper/Lower case

ToUpper()

int toUpper(int ch)
{
 if(ch>='a' && c<='z')
 return('A' + ch - 'a');
 else
 return(ch);
}

IsUpper()

int isUpper(int ch)
{
 if(ch>='A' && ch <='Z')
 return(1); //Yes, its upper!
 else
 return(0); // No, its lower!
}