I am a relative newbie to DreamweaverMX, and am teaching high school students how to design web sites using frames. I have a problem that hasn't shown up before - when I set my target to main page, the page that's supposed to go into the frame is opened in a brand-new window. (Of course, this happened when I was demonstrating the process to the kids!) Strangely, fully half of the kids had their pages open in the main frame with no problem; the remaining half had the same problem as I did. I'm pretty sure that I follwed the steps correctly, otherwise why would half of the kids who were following along with me have gotten it right?
If the target name is incorrect it will open a new window. Make sure the target name corresponds to the name specified in the root document.
<frame src="red.htm" name="main" target="main">
With that said please,please,please don't use frames, and especially don't pass the idea of using them to your students. On rare occasion a frame or iframe is necessary but in most cases frames are really bad.