[RESOLVED] Use Variable Value as the Object Property

[cbVision]

Greetings, I hope I worded this correctly. I'm trying to use a variable value as the object property name. For example:

var order = new Object();
order.orderid = 12345;

The problem is, orderid is stored as a value in another string. For example:

var propertyName = 'orderid';
var order = new Object();
order.propertyName = 12345;

How can I set order.orderid equal to something when "orderid" is stored in a variable?