subr area_wired, id
 ;we might have some other tools wired to response to subareas
 zeroifnotdefined, $hist_wired_flag, $flux_wired_flag, $light_wired_flag
 if $hist_wired_flag then {
 xmtextfieldsetstring, $hist_subarea, string(id)
 histplot_cb
 }
 if $flux_wired_flag then {
 xmtextfieldsetstring, $flux_subarea, string(id)
 fluxcompute_cb
 }
 if $light_wired_flag then {
 ;should use a text insert but we don't have that call (yet) so read back,
 ;append, and rewrite
 s = xmtextfieldgetstring($light_subareas)
 s = s + ' ' + string(id)
 xmtextfieldsetstring, $light_subareas, s
 }
 endsubr
 ;===============================================================================