function swap_over(id)
{
	var target = document.getElementById('button_reg_' + id);
	var dest = document.getElementById('button_down_' + id);
	if ( target.style.display == '' )
	{
		target.style.display = 'none';
		dest.style.display = '';
	}
}

function swap_out(id)
{
	var target = document.getElementById('button_down_' + id);
	var dest = document.getElementById('button_reg_' + id)
	target.style.display = 'none';
	dest.style.display = '';
}