function go_back()
{
	if (document.getElementById('send_form'))
		if (document.getElementById('send_form').style.display=='none')
			show_form();
		else
			history.back();
	else
		history.back();
}

function show_check()
{
	if (document.getElementById('send_form')&&document.getElementById('check_form'))
	{
		document.getElementById('send_form').style.display='none';
		document.getElementById('check_form').style.display='block';
	}
}

function show_form()
{
	if (document.getElementById('send_form')&&document.getElementById('check_form'))
	{
		document.getElementById('check_form').style.display='none';
		document.getElementById('send_form').style.display='block';
	}
}