Function:     irim_userlist

Purpose:      allocate memory to list and read snip.det list from the user

Category:     IRAS, private to program: IMAGE

Author:       Do Kester

Use:
int irim_userlist(
	list_type	*ls,
	int		deflev,
	char		*key,
	char		*mess )

returns: -1	memory allocation error
	 other	number of items returned

Comment:      This routine is not callable in FORTRAN

Updates:      06 Aug 1991: DK, Creation date
	      04 Jun 1992: DK, prepared for GIPSY library