Drag and Drop option within yahoomails

Why don't we have an option to drag an attachment from 1 yahoo mail to other yahoo mail.
Suppose we have an attachment in one yahoo mail and we want to attach the same attachment to the new mail. Generally in that case we save the attachment to the desktop or some other place in the PC and from there we attach it to the new mail which is a long process. Instead of doing all this it will be good if we have an option to Drag the attachment from one mail to the other as we have in the Outlook. This will definitely save some time.
Or when we click on the attachment an option which take the attachments from the existing yahoo mails.