drag.step(amount, container, center) -> jQuery.Drag
{number|Object}
make the drag move X amount in pixels from the top-left of container.
{optional:jQuery}
the container to move in reference to. If not provided, the document is used.
{optional:String}
Indicates how to position the drag element in relationship to the container.
{jQuery.Drag}
the drag object for chaining.
makes the drag move in steps of amount pixels.
Demo