Control can be hidden when page is first loaded by setting Hidden property to true. It can be displayed on demand by calling Show function of the client-side control object.
For instance, a button click event can be used to show/hide the control.
By default, the control is rendered inline, i.e it's rendered exactly where the control tag is inserted.
However it's also possible to display the control as a modal dialog by setting DisplayMode property to Window and setting WindowOptions sub-properties.