_tolower()              Convert 'c' to Lowercase (Macro)

 #include   <ctype.h>

 int        _tolower(c);
 int        c;                           Character to be converted

    _tolower() converts 'c' to lowercase. _tolower() is a macro.  It
    should be used only if you know that 'c' is an uppercase letter, as
    the result is undefined otherwise.

       Returns:     The converted character 'c'. There is no error
                    return.

         Notes:     Use tolower() to convert a character that is not
                    necessarily an uppercase letter.

   -------------------------------- Example ---------------------------------

    The following statements convert a string to lowercase before
    printing it.

           #include <ctype.h>
           #include <stdio.h>

           char string[15] = "ALPHABET";
           int x;

           main()
           {
               for (x = 0; x < strlen(string); x++)
                   printf("%c",_tolower(string[x]));
               printf("\n");
           }