function show_first_pop_up(){
		hide_second_pop_up();
		document.getElementById('first_pop_up').style.display='block';
	}
	function hide_first_pop_up(){
		document.getElementById('first_pop_up').style.display='none';
	}

	function show_second_pop_up(){
		hide_first_pop_up();
		document.getElementById('second_pop_up').style.display='block';
	}
	function hide_second_pop_up(){
		document.getElementById('second_pop_up').style.display='none';
	}