TIWCGJQSortableOptions.Containment Property
Constrains dragging to within the bounds of the specified element - can be a DOM element, 'parent', 'document', 'window', or a jQuery selector. Note: the element specified for containment must have a calculated width and height (though it need not be explicit), so for example, if you have float:left sortable children and specify containment:'parent' be sure to have float:left on the sortable/parent container as well or it will have height: 0, causing undefined behavior.
published property Containment: string index 05 read GetStringValue write SetStringValue stored IsStringStored;
Property Value
Type: string