function getObjById(id) {
	if (document.getElementById) {
		return document.getElementById(id);
	}
	if(document.all){ 
		return document.all[id];
	}
	if (document.layers) {
		return document.layers[id];
	}
}

function calcPrice()
{
	pyform = document.forms['frmpay'];

	my_users = pyform.elements['my_users'].value;
	if ((!(/^\d+$/.test(my_users))) || my_users==0)	//用正则表达式判断my_users不是正整数。
	{
		if (my_users!='')	//如果my_users不为空
			pyform.elements['my_users'].value=1
		my_users=1
	}

	var price = 0;
	if ( my_users < arrPrices[0+1] )
		price = arrPrices[0];
	else if ( my_users < arrPrices[2+1])
		price = arrPrices[2];
	else if ( my_users < arrPrices[4+1])
		price = arrPrices[4];
	else if ( my_users < arrPrices[6+1])
		price = arrPrices[6];
	else if ( my_users < arrPrices[8+1])
		price = arrPrices[8];

	var total = price*my_users;
	getObjById('totalcost').innerHTML='<b>' + total.toFixed(2) + '</b>';
	pyform.elements['item_name'].value='e-Pointer Site License ' + my_users + ' Users';
	pyform.elements['amount'].value=total.toFixed(2);

	return total;
}