Displa a pop up message with a drop down list

Hello,

One of our Business requirement is to display a pop up with a drop down list(to update a field) when the user click a customiszed button  on an applet, this button calls a workflow that calls a business service for a validation rules.

One of our thought is to display a message with a pop up message to confirm or not, with pressing Ok, we will update the field , if the user press Cacel, we keep the field with defalt value.

we need to use the browser scripts for that, my question is can we invoke (call) a Browser script from a server scripts (from the customized business Service, that already exists)