string 0;                       \use zero-terminated string convention
include c:\cxpl\stdlib;         \ToUpper, ToLower, and 'code' declarations

proc StrToUpper(S);             \Convert string to uppercase characters
char S;
while S(0) do [S(0):= ToUpper(S(0));  S:=S+1];

proc StrToLower(S);             \Convert string to lowercase characters
char S;
while S(0) do [S(0):= ToLower(S(0));  S:=S+1];

char Str;
[Str:= "alphaBETA";
StrToUpper(Str);
Text(0, Str);  CrLf(0);
StrToLower(Str);
Text(0, Str);  CrLf(0);
]