Removing attachment from new post\thread

[vsub_]

Is this feature missing or I just don't see it.
If you choose a file to upload as attachment,you'll get an error if the file is too big when you try to upload it.

Ok but I don't see a "Remove" button.
If I choose I file which is too big,the only way I can post my post is by going back and click again on the new post\thread button and type again what I wanted to say.
If I try to post without clicking on the "Add Attachment" button,it will again try to automatically upload the file which will result in error page