Removes mouse capture from the object in the current document.
Returns S_OK if successful, or an error value otherwise.
For IHTMLElement2::releaseCapture to have an effect, you must set mouse capture through the IHTMLElement2::setCapture method.
You can invoke the IHTMLElement2::releaseCapture method on the document object. The IHTMLElement2::releaseCapture method makes it unnecessary to determine which element has capture to programmatically release it. Other actions that release document capture include displaying a modal dialog box and switching focus to another application or browser window.