PWtest: Checking whether a tag exists

Purpose

Various versions of ProWesS can have various new tags (see the PW function for the use of tags). If you use a tag that doesn't exist in the system, your program will stop with an error (returned by the PW function). This can happen twice: either if the ProWesS Basic Interface itself does not recognize the tag, or if the type does not know what to do with the tag sent to it.

This function can tell you whether a tag is recognized by the Basic Interface (i.e. the PW function) or not. For the type, see the PWchange% function.

Syntax

The syntax of this command is quite simple:

result%=PWtest(tag$)

where result% is 1 if the tag exists, 0 if not.

Example

         result%=PWtest('LABEL_UNDERLINE')

this tells you if this tag exists or not.
PROGS, Professional & Graphical Software
last edited 1997 Jun 06 (wl)