NAME:
	lhr_wolstencroft
 PURPOSE:
       This routine calculates the likelyhood ratio and reliability for a set
	of identifications according to Wolstencroft et Al. 1986 
	It returns a 2-D vector containing the LHR values (1st D: x sources, 
	2nd D: candidates, 2nd D is 600, LHRs are zero beyond last candidate)
 CALLING SEQUENCE:
	result=lhr_wolstencroft(xmmdb,wfcdb[,dmax,radec_err=radec_err,$
	radec_fromdb=radec_fromdb])
 INPUTS:
	xmmdb: xmm database 
	wfcdb: wfc dbatabase for extracting magnitudes of candidates
 OPTIONAL INPUT PARAMETERS:
	dmax: max. offset for nearest matches
	radec_err: no (an error to be assigned to every xmm position)
	radec_fromdb: if set, position error extracted for each object from
		xmmdb
 OPTIONAL OUTPUT PARAMETERS:

 RESTRICTIONS:
	UNTESTED
 CALLED PROCEDURES:
	
 MODIFICATION HISTORY:
	Original by Ignas Snellen
	08-Dec-2000  S. Aigrain: adapted as a separate function
	16-Jan-2001  S. Aigrain: wolsencroft method separately

(See /home/xmmssc/soft/idl/pro/lhr/lhr_wolstencroft.pro)