How do I close a popup window?

I have a text link popup that opens when I click the link. This link contains content that needs to be previewed then closed afterwards. The default window that displays has no toolbar when it displays so there is no way to close the popup browser window.

I tried adding a close button in the page that displays and added javascript to it. But, apparently what I thought was the window name in javascript isn't. So, I cannot get my popup windows to close. Can someone help with simple workaround solution. Thanks.