Using popups in ColdFusion

how you go about it depends on how the order number is selected on your form page.
if the form page already knows the order number when it loads (i.e. the order was selected on a previous page and then passed to the form page as a url variable or in some other way), then you can just use your cfoutput inside the javascript's alert text.
if the order is selected on the form page after it loads. then you need to store the order number as a javascript variable of in a (hidden) form field. with the form field option, if an order is selected in a form field (i.e. in a drop-down select list or a checkbox), then you can
1) access that form field's value in your javascript alert
or
2) add a onChange or onClick event to that form field and write a javascript function that will store the selected order number somewhere (i.e. in a variable or another form field), and then use that variable or form field value in your alert code.

feel free to PM me with your full page code and i will help you decide which way to go and write the appropriate code, if you want to.

You can either add it to the popup url as a url value pair or as well as displaying it have a hidden form field and then access the value of the hidden form field from the popup

Ken