function calculate_price(){
	var quantity = $('quantity-field').get('value');
	var price = $('per-ea-price').get('text');
	var price_m1 = $('per-ea-price-m1').get('text');
	
	$('total-price').set('text', price*quantity);
	$('total-price-m1').set('text', price_m1*quantity);
	
}