probable gtk_window_present and pango help

[Rudra Banerjee <bnrj rudra yahoo com>]

Dear Friends,
Here is a minimal example of a program, where if i click the button, a
pop up window appears. I am posting both the call back function and the
main routine (table.c).
I am facing 2 problem.
1) The problem is evry time I click the button "main", a new window
appears(obviously). What I want to achive is, if the window is already
present, it should not open again; rather it should focus that window. I
believe, this can be achived by gtk_window_present(may be I am wrong).
But I don't know how to use it.

2) In the callback function, I have C_1 and C_2. What I want to achive
is C<sub>1</sub> etc via pango(or any other).

I am not a C programmer. And this is my *first* GTK as well.
So, I am posting both the code. I will be grateful if anybody take some
time to suggest me how to get things done.
Regards and Best,

//###########################
//#       FILE TABLE.C
//############################
#include <gtk/gtk.h>
#include <stdio.h>
#include <string.h>
#include <gdk/gdk.h>
GtkAccelGroup *menuGroup;
GtkWidget  *window1 ;
GtkWidget *window;
GtkWidget *button;
GtkWidget *table;
GtkWidget  *vbox1 ;
GtkWidget  *menubar ;
GtkWidget  *helpmenu ;
GtkWidget  *helpmenu_menu ;
GtkWidget  *helphelp ;
GtkWidget  *helpabout ;

#include "prop_label.c"

int main( int   argc,
          char *argv[] )
{
    GtkWidget *window;
    GtkWidget *button;
    GtkWidget *table;

    gtk_init (&argc, &argv);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title (GTK_WINDOW (window), "Main");
    gtk_container_set_border_width (GTK_CONTAINER (window), 20);


/*
 * MENU BAR
 */
    vbox1 = gtk_vbox_new (FALSE, 0);
    gtk_container_add (GTK_CONTAINER (window1), vbox1);

    menubar = gtk_menu_bar_new ();
    gtk_box_pack_start (GTK_BOX (vbox1), menubar, FALSE, FALSE, 2);


/* INITIALIZE THE TABLE
 */
    table = gtk_table_new (1, 1, TRUE);
    gtk_box_pack_start (GTK_BOX (vbox1), table, FALSE, FALSE, 2);
    gtk_container_add (GTK_CONTAINER (window), vbox1);

    /* Color Scheme */
    GdkColor colorBlue = { 0x0000, 3598, 57054, 61937 };

/* Create first button */
    button = gtk_button_new_with_label ("main");
    g_signal_connect (button, "clicked",
                      G_CALLBACK (callback_it), (gpointer) "Call");
    gtk_table_attach_defaults (GTK_TABLE (table), button, 0, 1, 0, 1);
    gtk_widget_modify_bg( button, GTK_STATE_NORMAL, &colorBlue );
    gtk_widget_show (button);



    gtk_widget_show (table);
    gtk_widget_show (window);
    gtk_widget_show_all (window);

    gtk_main ();

    return 0;
}

/*###########################
#       FILE PROP_LABEL.C
############################*/

#include <gtk/gtk.h>

int callback_it( int   argc,
          char *argv[] )
{
  static GtkWidget *window = NULL;
  GtkWidget *hbox;
  GtkWidget *vbox;
  GtkWidget *frame;
  GtkWidget *label;


  /* Initialise GTK */
  gtk_init(&argc, &argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title (GTK_WINDOW (window), "Callback");
  vbox = gtk_vbox_new (FALSE, 0);
  hbox = gtk_hbox_new (FALSE, 0);
  gtk_container_add (GTK_CONTAINER (window), hbox);
  gtk_box_pack_start (GTK_BOX (hbox), vbox, FALSE, FALSE, 0);
  gtk_container_set_border_width (GTK_CONTAINER (window), 25);


  frame = gtk_frame_new ("C_1");
  label = gtk_label_new ("1\n2\n3");
  gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_LEFT);
  gtk_container_add (GTK_CONTAINER (frame), label);
  gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);

  frame = gtk_frame_new ("C_2");
  label = gtk_label_new ("1\n2\n3");

  gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_LEFT);
  gtk_container_add (GTK_CONTAINER (frame), label);
  gtk_box_pack_start (GTK_BOX (hbox), frame, FALSE, FALSE, 0);

  gtk_window_set_resizable(GTK_WINDOW (window), FALSE);
  gtk_widget_show_all (window);
}