Passing a value to a popup window

Is there a way to pass a value to a popup window.
I have buttons for each machine, can I pass the machine number to the popup window to use on some of the queries ?
is there a better way to create a pop up window to use for all the machines?

Check out the docs for system.nav.openWindow. The second code example shows how to pass a couple of parameters to custom properties on the window.