char *strleft(char *b, char *s, int i)
     {
          char *a;
          int  x;
          a = b;
          for (x = 1; x <= i; ++x)
               *b++ = *s++;
          *b ='\0';
          return(a);
     }
     
char *strmid(char *b, char *s, int  i, int j)
     {
          char *a;
          int  x;
          a = b;
          if ( j != 0 ){
               for (x = 1; x < i; ++x){
                    if (*s++ == '\0'){
                         *b = '\0';
                         return(a);
                    }
               }
               for (x = 1; x <= j; ++x)
                    *b++ = *s++;
          }
          *b = '\0';
          return(a);    
     }