You can view multiple documents
in a single Document window by using tabs to identify each document.
You can also display them as part of a floating workspace, in which
each document appears in its own window.
Select Dreamweaver >
Preferences, and then select the General category.
Select or deselect Open Documents in Tabs, and click
OK.
Dreamweaver does not alter the display of documents that
are currently open when you change preferences. Documents opened
after you select a new preference, however, display according to
the preference you selected.