There are two basic way to open new window
1) Using Window.Open() and
2) Using Window.showModalDialog()

The Syntax for using these methods are

. Window.Open(URL,WindowName,Window Features)

Example:

window.open ("http://www.dotnetfunda.com","mywindow","status=1,toolbar=1");

. window.showModalDialog(URL,WindowName,ModalDialog Features)
for example:

window.showModalDialog("http://www.mindstick.com", "mywindow","dialogWidth:400px;dialogHeight:395px");