Hello Teena,
You can set the
AllowedFileExtensions property of the RadAsyncUpload to ".doc" so that the user wont be able to select files with extensions other than .doc. When you set this property, files with other extensions wont be displayed in the File browser window.
RadAsyncUpload provides client-side event called
OnClientValidationFailed.
It is fired when the selected file has invalid extension or its size is higher than
the MaxFileSize property.
ASPX:
JavaScript:
Thanks,
Princy.