NAME:    
	plot_lognlogs
  PURPOSE: 
	plot no sources with flux > S vs S to screen or ps file 
	from an xmm database of the xmmout.fits type
  CALLING SEQUENCE: 
	plot_lognlogs,db[,outfile]
  INPUTS: 
	db: name of database to search
  OPTIONAL INPUT KEYORDS:
	offmax: max offax angle of xmm objects to be included. I f not set all 
		objects are included.
  OPTIONAL OUTPUT KEYWORDS: 
    	ps: optional output ps file the plots will be sent to. 
       gif: same as above for gif output, but without '.gif' bit
		only active is ps is not set
	If neither is set, the plots will be sent to screen.
  EXAMPLE: 
	plot_lognlogs, 'xmmdb',ps='lognlogs.ps'
  RESTRICTIONS: 
        UNTESTED
  CALLED PROCEDURES AND FUNCTIONS: 
	astrolib functions
	select_offax,select_cond
  MODIFICATION HISTORY: 
     	09-Oct_2000  Original by Suzanne Aigrain

(See /home/xmmssc/soft/idl/pro/xmm_plots/plot_lognlogs.pro)