expression.DefaultTargetFrame
expression Required. An expression that returns a Document object.
Remarks
While the DefaultTargetFrame property can use any user-defined string, it has the following predefined strings: "_top", "_blank", "_parent", and "_self".
Example
This example sets Microsoft Word to open a new blank browser window when a user clicks on hyperlinks in the active document.
Sub DefaultFrame()
ActiveDocument.DefaultTargetFrame = "_blank"
End Sub