How to forward a ModalDialog to a new url

Last few days I was fighting with Modal Dialog ( opened with the method showModalDialog ) to forward to a new page with out opening a new window.The usual
document.location.href = newurl;
works but opens in a new window. Then I got a simple solution. window.name = "somename"
window.open(newurl, window.name)
well this works very fine. It opens the new url in a wondow with the name "somename". Since that is our modal dialog is "somename" destination url opens in this modal dialog.