"Create folder" dialog closes without error message in file manager when no folder name is given

When using the "Create folder" dialog in the file manager, if one clicks on the "Create folder" button without first providing a folder name the dialog is hidden and process cancelled. It would be preferable if the user received an error message similar to that during the folder rename process if no name is provided.

Reproduction steps:

1. Click on the "Create folder" link in the file manager (anywhere - private files, File Resource modedit, etc)
2. Leave the "Enter a name:" text box empty or add spaces, but no other characters
3. Click the "Create folder" button

Actual result: New folder creation dialog automatically closes when user clicks "Create folder" button without entering the folder name.
Expected Result: User should be alerted with appropriate message when folder name not entered and clicks on Create folder button.