Telerik does not offer support for customizations of the built-in dialogs of RadEditor. We can only guide you but it is up to the developer to implement the requirements of his/her project.
If you want to help you, please open a support ticket and send a simple working project that demonstrates what you have done and what you want to achieve? Please, include all project files, because I need a runnable project that I can test and modify.
You can attach zipped projects only in the support ticketing system but not in the forums.
It is also important to know that the built-in dialog files are changed and enhanced and if you use an older version of the RadEditor you will be unable to use the latest version of the Find And Replace dialog that I attached in my earlier reply.
My suggestion is to also upgrade to the latest build of Telerik.Web.UI.dll which is 2011.2.712 (Q2 2011) which offers support for the latest modern browsers.
the Telerik team
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