_self
Instructs the browser to display the new document in the same frame and window as the hyperlink that loads it. All frames target themselves by default, so this name is not very useful or necessary. _parent
Instructs the browser to display the new document in the parent frame of the frame containing the hyperlink that loads it. If the frame has no parent, then this name has the same effect as _self. _top
Instructs the browser to remove all frames and display the new document in the entire window. If there are no frames, then this name has the same effect as _self. This target makes it possible to "exit" a framed document. _blank
Instructs the browser to display the new document in a new, unnamed window.