-<H2>RETURN VALUE</H2><PRE>
- All routines return the integer <STRONG>OK</STRONG>. The SVr4.0 manual
- says "or a non-negative integer if <STRONG>immedok</STRONG> is set", but
- this appears to be an error.
+<H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ All routines return the integer <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on
+ failure. The SVr4.0 manual says "or a non-negative inte-
+ ger if <STRONG>immedok</STRONG> is set", but this appears to be an error.
+
+ X/Open defines no error conditions. In this implementa-
+ tion, functions using a window pointer parameter return an
+ error if it is null.