I have an app that makes extensive use of iframes. (Yes, I know, unfashionable... no lectures please.) Essentially, it builds the top page with menu items on the left, and then loads the target of those menu items into an iframe 'content' on the right. The rationale is that as a visitor cycles through menu items, most of the page doesn't change, therefore, there's no point reloading it.
The top page will have html something like this...
<a href = 'somescript.php' target='content'>Something
<iframe id='content' name='content' src='blank.php'></iframe>
This problem has me baffled...
It mostly works, but occasionally, and for no reason that I've been able to detect, you will click on a menu item, the target of which is definitely set to 'content', and the browser will open a new window (or tab). It happens in IE, FF, Iron/Chrome and Safari.
I looked at the html doc type and changed it to
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd
That helped, in that the wayward loading occurs less frequently, but it hasn't eliminated it altogether.
I'm open to suggestion.