;+
;NAME:
; thm_ui_set_active_dset
;PURPOSE:
; sets active datasets in themis GUI to given tplot varnames, used in
; the call_tplot widget.
;CALLING SEQUENCE:
; ss = thm_ui_set_active_dset(active_names, state)
;INPUT:
; active_names = the tplot variable names
; state = the widget state structure for the master widget
;HISTORY:
; 22-jan-2007, jmm, jimm@ssl.berkeley.edu
;
;$LastChangedBy: kenb-mac $
;$LastChangedDate: 2007-01-26 15:52:34 -0800 (Fri, 26 Jan 2007) $
;$LastChangedRevision: 241 $
;$URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/thmsoc/trunk/idl/themis/common/thm_ui_set_active_dset.pro $
;
;-
Function thm_ui_set_active_dset, varnames, wstate

  data_ss = -1
  temp_names = tnames()
  data_ss = where_arr(temp_names, varnames)
  If(data_ss[0] Ne -1) Then Begin
    If(ptr_valid(wstate.active_vnames)) Then ptr_free, wstate.active_vnames
    wstate.active_vnames = ptr_new(varnames)
;Set ptrs and ids in the themis_w state
    thm_ui_set_state_ptrs, wstate
  Endif Else message, /info, 'No valid names to set'
  Return, data_ss
End