Synopsis:
   $tolower(text)
   $toupper(text)

Technical:
   This $toupper() function converts all occurrences of characters in the
   range a..z to their uppercase counterparts, A..Z.  Its counterpart,
   $tolower(), does just the opposite, converting from A..Z to a..z.

Practical:
   This basically converts the entire input string to all capital or all
   lowercase letters, depending on the function used.

Returns:
   input string with case converted

Examples:
   $toupper(Hello there.)          returns "HELLO THERE."
   $tolower(Hi Bob!)               returns "hi bob!"

See Also:
   tr(6)

Restrictions:
   These functions only work on 7-bit ascii letters.  They will not convert
   8-bit letters with the high bit set (i.e. European characters that have
   accents, graves, etc.).  Use $tr() instead.