var d = document;

function form_changer(on, off) {
	var toggler = d.getElementById('toggler');
	var span = toggler.getElementsByTagName('span');
	var enable = d.getElementById(on);
	var disable = d.getElementById(off);
	
	enable.style.display = 'block';
	disable.style.display = 'none';
	
	if(on == 'domestic'){
		span[0].className = 'on';
		span[1].className = 'off';
	} else if(on == 'oversea'){
		span[0].className = 'off';
		span[1].className = 'on';
	}
}