The code in the demo opens a new RadWindow for each tab:
oWnd = radopen(itemUrl,
More information on how this works is available in this help article
In the code we have been working on you always pass a static name for the RadWindow, thus you do not create a new one for each tab:
oWnd = radopen(pUrl, pName);
You should either provide a new RadWindow, or check if it already has a corresponding tab - if it does - avoid creating a new tab.
A main issue here is also that you dispose the TabStrip, so the dynamic JavaScrtipt fields (tab.correspondingWnd) are destroyed as well. If you do not dispose it (as I advised in my previous post) things will work without many further modifications. Otherwise I advise that you find a different way to keep this reference, for example a global JS array, but this is a rather uncertain way.
What I advise is that your review your entire logic thoroughly and see where the omissions are and how it can be improved (I mainly advise that you use AJAX only for a button to fetch the URL from the server and leave the TabStrip on the page).
the Telerik team
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