Description of problem:
In my Observation, when user creates attachments without description, the current bugzilla tool reloads the page once user click on "Submit" button. And then the next page get loaded with Error "You must enter a description for the attachment". Now, if user press Back to try again, then the page get again reloaded and shows the create attachment page. Now, user need to write some description for the desired file to be attached. 
Instead of reloading page and showing error, if one pop up window appears with the error, keeping the page intact, and shows the same error and one "OK" button which can be clicked to get focus on attachment page, and the cursor should blink on the Description text field, then the page reloading time can be saved and the performance can be optimized more.
Developers, I am expecting some feedback, suggestions or your view on this. :)

Version-Release number of selected component (if applicable):
bugzilla-3.4.6+

How reproducible:
Always

Steps to Reproduce:
1. Login to https://bugzilla.redhat.com
2. Either open an existing bug or create a dummy one.
3. Go to Create New Attachment Page.
4. Browse any file to be attached.
5. Keep the Description Field Vacant. (Do not write any description)
6. Click on "Submit" Button
7. Observe the new page appears with error message.
  
Actual results:
A new page is getting reloaded with error message, which is taking reloading time and as well as roll back time to go back to the attachment page, increasing the total response time of usage for creating an attachment.

Expected results:
Instead of showing error message in another page, if one pop up window appears keeping the current page intact, with the error message, the time can be saved for reloading and roll back to main page.

Additional info: