I am building a SharePoint 2010 intranet. I want to get rid of the master page heading in the popup dialog box (Upload document and display other things). How can I get rid off the master page heading for this dialog alone.
If I read your question correctly, you have changed the master page and some elements like logo or navigation or some such now appear in the modal dialogs. To hide these elements in the dialogs, you can apply the class "s4-notdlg" to each of the unwanted elements.