I have a site collection in Sharepoint Designer 2013. When my homepage opened, I want to get a pop-up. The pop-up is a image. It isn't a webpage. How can do this? Is there such a thing?
CustomAction to your
window.open() or SharePoint's
See, for example:
and other questions tagged modal-dialog
Otherwise, you can add a HTML form web part on your home page and edit the source to look like
See window.open documentation for details.