Trigger ModalPopupExtender from LoadPage Event instead of Control

Is it possible to have the modal dialog appear when a page is first loaded? It appears that it only works from a control (TargetControlID) like a button.

Create a LinkButton that has style="display: none;" and make this the target control of the ModalPopup. Then call the server side Show() or the client side show() method to display the modal popup manually whenever you need to.