;+
; NAME:
;	www_help_mailto
; PURPOSE:
;	Encode emai address for insertion in web page
; CATEGORY:
;	gen/idl
; CALLING SEQUENCE:
	FUNCTION www_help_mailto, email, href=href, title=title, subject=subject
; INPUTS:
;	email				scalar; type: string; default: none
;							if no email address is specified then the
;							null string is returned
; OPTIONAL INPUT PARAMETERS:
;	/href				if set, return full HTML mailto string, i.e.
;							<a href="mailto:email?subject=text">title</a>
;
;	Only used if /href is set:
;
;	title=title 		scalar; type: string
;							text to be used in HTML mailto string
;	subject=subject 	scalar; type: string; default: none
;							text for email subject field
; OUTPUTS:
;	mailto				scalar; type: string	encoded email address
; INCLUDE:
	@compile_opt.pro				; On error, return to caller
; CALLS:
;	IsType, InitVar
; PROCEDURE:
;	Email address is replaced by sequence of HTML special chars (using
;	ascii codes).
; MODIFICATION HISTORY:
;	DEC-2006, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;-

mailto = ''

IF IsType(email,/string) THEN BEGIN

	mailto = '&#'+strjoin(string(byte(email),format='(I3.3)'),';&#')+';'

	InitVar, title, mailto
	InitVar, href , /key

	mailto = '&#'+strjoin(string(byte(email),format='(I3.3)'),';&#')+';'

	IF href THEN BEGIN
		mailto = '<a href="mailto:'+mailto
		IF IsType(subject,/defined) THEN mailto += '?subject='+subject
		mailto += '">'+title+'</a>'
	ENDIF

ENDIF

RETURN, mailto  &  END