why it can't get text buffer?

["Mee Com" <writemessage hotmail com>]

Hi!
     I had tried many times to get text buffer (the thing that I want to do 
is to receive text from the first pane widget and send it to the second pane 
widget and display that text on this second pane widget,which both pane 
widgets are on the same window)
    but it can't get text buffer!I don't know why.........
    I had created function like this,

    void send_recieve_text (GtkWidget *widget,GtkWidget *text)
   {
      inbuffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text)); /*Get 
text from input pane*/
      gtk_text_buffer_get_start_iter  (inbuffer,&iterstart);
      gtk_text_buffer_get_end_iter    (inbuffer,&iterend);

     data_from_input = gtk_text_buffer_get_text 
(inbuffer,&iterstart,&iterend,TRUE);
     incount = gtk_text_buffer_get_char_count  (inbuffer);

     outbuffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));/*To show 
on output pane*/
     gtk_text_buffer_get_iter_at_offset (outbuffer, &iterout, -1);

    gtk_text_buffer_insert(outbuffer,&iterout,data_from_input ,incount);   
/*Show Output*/

   }

I had tried,and it seems that this line won't work ......
data_from_input = gtk_text_buffer_get_text 
(inbuffer,&iterstart,&iterend,TRUE);
that I really don't understand about the reason why it can't change buffer 
to text?,

could anybody give me some advice,please?or some example about how to send 
buffer and to be show text?

(In the GTK2.0 tutorial only has example about to show some constant like 
this......
gtk_text_buffer_set_text (outbuffer,"Hello",-1);
but it can't work if I change "Hello" to any of variable.

Thanks lot for all of your advices,
Regards,

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