If point is on a keyword, help for that keyword will be shown. If
point is on a routine name or in the argument list of a routine, help
for that routine will be displayed. Works for system routines and
-keywords, it pulls up text help. For other routies and keywords,
+keywords, it pulls up text help. For other routines and keywords,
visits the source file, finding help in the header (if
`idlwave-help-source-try-header' is non-nil) or the routine definition
itself."