How can I specify which MIME types to check? That was my initial question. How do I set the ValidateOption.AllowedFileMimeTypes property? Would you please give me an example?

Also, this link that you provided (http://www.ajaxuploader.com/document/index.htm#page=html/How-to-catch-uploader-error.htm) does not give specific instructions on how to catch the MIME error. What do the parameters of the CuteWebUI_AjaxUploader_OnTaskError event do? How can I know if this is the MIME error?

CuteWebUI_AjaxUploader_OnTaskError(obj,msg,reason)