Ajax Behaviour On File Upload

[Deepak Naithani]

i am having <p:fileupload >

<p:fileUpload id="uploadExcel" process="@this"
                   fileUploadListener="method in backing bean"
                   invalidFileMessage="Only files with extension xls are accepted" allowTypes="/(\.|\/)(xls)$/"
                   label="Import Users From Excel Workbook">
                   <p:ajax event="        " listener="textarea is updated"
                   update="newsLetterRecipients,uploadExcel">
                   </p:ajax>
</p:fileUpload>


<h:inputTextarea value=" "
			id="newsLetterRecipients" rows="2" style="width: 100%">
			</h:inputTextarea> 

User can enter values in textarea from database or can be uploaded by file upload (in xls format). Is there any value for event attribute for fileupload. I want to call a method on fileupload to with ajax behaviour will be called and textarea will be updated

Thanks in Advance.