The purpose of this plugin is to provide a means to prevent form SELECT boxes and other system controls from obscuring popups in IE version 5.5 and higher. If makes use of a change in the way that IE handles an IFRAME element starting with version 5.5. Previous versions of IE and Netscape 4.x, required that the user place these elements in a layer (i.e., a positioned DIV container), which is hidden when the popup appears above it and is reshown when the popup is hidden. It appears that these steps are not needed for either Opera 7 or Netscape 7.1 but does appear to be necessary for handling these FORM elements in earlier versions of Netscape 7. Unfortunately this same approach doesn't work in Netscape 6 which still places the scroll controls of the SELECT box above the popup. The coding of this plugin has been expanded to allow these FORM elements to be hidden when an overlib popup appears above them so that this obscuring factor is removed in versions of IE prior to 5.5 and for the early versions of Netscape 7. While the code is implemented with Netscape 6, it has no affect on the appearance of the scroll controls, as noted above.
To include support for this plugin just include the following statements in the HEAD section of your document:
You only have to make sure that the
is loaded after the core module.
Download this plugin as a zip file.
The mechanism works by using an IFRAME shim as explained in this article. The arrangement of this IFRAME shim and the actual popup content is illustrated schematically in Figure 1 below. This same approach has been adopted in the Bubble and Shadow plugins.
Figure 1. Schematic illustration of shim and popup content
There are no formal command parameters associated with this plugin because everything is handled automatically when this plugin is loaded. Note that this plugin provides no support for Netscape 4.x, which doesn't understand the IFRAME element. For the other browsers mentioned above, SELECT boxes are merely hidden when the popup appears above them and then is reshown when you mouse off of the triggering link [NOTE: In Netscape 7, the popup is sometimes not completely hidden when mousing off the triggering link (the left and top edge still appear), which is most probably a rendering problem with the browser because if the page is scrolled so that the SELECT box is hidden by the bottom edge of the browser window and then reshown, this popup remembrant disappears.] To demonstrate how well it works I give here an example with a SELECT box that is covered by the popup :