Isc alpha

Type Function: BOOL

Input IN	BYTE (characters)
Output	BOOL (TRUE IN a sign of a..z, A..Z or Umlaut ) is
	ISC_ALPHA tests whether the character IN is an alphabetic character. If IN is a sign A..Z, a..z or any umlaut, the function returns TRUE, if not the function returns FALSE. In examining the Global Setup EXTENDED_ASCII constant is considered. If EXTENDED_ASCII = TRUE the extended ASCII character-set to be considered in accordance with ISO 8859-1. Umlauts like Ä, Ö, Ü are considered only if the global constant EXTENDED_ASCII = TRUE.
The following Table Explains the code

Code	EXTENDED_ASCII = TRUE	EXTENDED_ASCII = FASLE
0..64	FALSE	FALSE
65..90	TRUE	TRUE
91..96	FALSE	FALSE
97..122	TRUE	TRUE
123..191	FALSE	FALSE
192..214	TRUE	FALSE
215	FALSE	FALSE
216..246	TRUE	FALSE
247	FALSE	FALSE
248..255	TRUE	FALSE