Len

Reports the length of a string in characters.

Len ( string )

Argument	Description
string	The string for which you want the length

Long. Returns a long containing the length of string in characters if it succeeds and –1 if an error occurs.

This expression returns 0:

Len("")

This validation rule tests that the value the user entered is fewer than 20 characters:

Len(GetText()) < 20