;+
;NAME:
; thm_ui_update_history
;PURPOSE:
; Adds the string input to the state structure history array
;INPUT:
; string = a string to add to the history array
; state = the themis_w state structure, 
;OUTPUT:
; state.history is updated
;HISTORY:
; sep-2006, 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_update_history.pro $
;
;-

Pro thm_ui_update_history, string, state
  history = *state.history
  If(is_string(history[0]) And is_string(string)) Then Begin
    If(strupcase(strcompress(/remove_all, history[0])) Eq 'NONE') Then Begin
      history = temporary(string)
    Endif Else Begin
      history = [temporary(history), temporary(string)]
    Endelse
    ptr_free, state.history
    state.history = ptr_new(history)
  Endif Else message, /info, 'No history?'
  Return
End