function pop_up(which, title, width, height, scrollbars)
{
	my_pop_up= window.open(which, title,'width='+ width +',height=' + height + ',scrollbars=' + scrollbars + ',resizable=no');
    if (my_pop_up != null) 
	{
    	if (my_pop_up.opener == null) 
		{
      		my_pop_up.opener = self
   	}
		my_pop_up.window.focus();
	}
}