istag(3G)

NAME
     istag - returns whether a tag exists in the current open object

FORTRAN 77 SPECIFICATION
     logical function istag(t)
     integer*4 t

PARAMETERS
     t   expects the tag identifier that you want to test.

FUNCTION RETURN VALUE
     There are two possible return values for this function:

     .TRUE.    indicates that tag t exists in the current open object.

     .FALSE.   indicates that tag t does not exist in the current open object.

     The return value is undefined if no object is currently open for editing.

DESCRIPTION
     istag returns whether or not a tag is exists in the object currently open
     for editing.  If maketa has been called to create a tag, and deltag has
     not been called to delete it, istag returns .TRUE.  for it.

SEE ALSO
     deltag, gentag, isobj, maketa

NOTE
     This routine is available only in immediate mode.