The resize property allows the author to specify whether or not an element is resizable by the user, and if so, along which axis/axes.
object.style.resize = "value";
<'resize'> = none | both | horizontal | vertical
The user agent does not present a resizing mechanism on the element, and the user is given no direct manipulation mechanism to resize the element.
The user agent presents a bidirectional resizing mechanism to allow the user to adjust both the height and the width of the element.
The user agent presents a unidirectional horizontal resizing mechanism to allow the user to adjust only the width of the element.
The user agent presents a unidirectional vertical resizing mechanism to allow the user to adjust only the height of the element.
World Wide Web Consortium (W3C)