Part of why frames were SUPPOSED to go the way of the dodo twelve YEARS ago, but the ignorant and inept keep making new websites using them.
Much like the target attribute itself -- which along with frames have no business being used on websites after 1998.
-- edit --
WAIT, where are you putting target? Target needs to go on the ANCHOR, which you aren't doing... not sure what element you're choosing for that "target" part in DW, but it's probably the wrong one as I cannot find target="_blank" ANYWHERE in your code... except... the form? Form doesn't have a target attribute, even in frames.... not that I'm seeing a form on the page so what's with all that code?!?
Dreamweaver -- blight upon the Internet that tricks people into thinking they can make websites... such a harsh and cruel joke.