Multiple types supported: Number: The dialog will fade out while animating the height and width for the specified duration. tring: The dialog will be hidden using the specified jQuery UI effect. See the list of effects for possible values. Object: If the value is an object, then effect, delay, duration, and easing properties may be provided. The effect property must be the name of a jQuery UI effect. When using a jQuery UI effect that supports additional settings, you may include those settings in the object and they will be passed to the effect. If duration or easing is omitted, then the default values will be used. If delay is omitted, then no delay is used.