I am using HTML Pop-ups to display feature attachments in ArcGIS Desktop 10.5. The attachments are single web pages (mht). I am able to display the links to the attachments using an XSL template format. When a link is clicked, the mht file is opened in ArcGIS's built-in web browser but the size of the window is very small. Is there any way in the XSL template to specify the size of the built-in web browser window when the link is clicked? Thanks for any help!