NAME:
	link_blank
 PURPOSE:
	makes a blank 200x200 gif image and links it to the file names of any 
	xmm or poss gifs whose bands are not there
 CALLING SEQUENCE:
	link_blank_xp,xmmdb[,flags=flags]
 INPUTS:
	xmmdb: the path name of database to take xmm record nos from.
 OPTIONAL INPUT AND OUTPUT KEYWORDS :
	flags:  9 element string array where each element is 'y' or 'n' 
       depending on wether the corresponding data is present or not. 
       Order: xmm 25,xmm 52,xmm 24,xmm 41,xmm 57,poss1 red, poss1 blue, 
	poss2 red, poss2 blue.
       default is all 'y'
 OUTPUTS:
	'hmtl/gif/blank.gif' plus all the linked ones
 EXAMPLE:
	
 CALLED PROCEDURES:
	mkgif
 MODIFICATION HISTORY:
	10-Nov-2000  Original by Suzanne Aigrain

(See /home/xmmssc/soft/idl/pro/html_tables/link_blank_xp.pro)