What I have is a link 'What is this?' and I want, when clicked upon, for an alert box to popup. I should be able to specify the text contained in the alert box, and for there to just be one button, an 'OK' button. I'm sure this is quite easy, I'm guessing it's something to do with onclick= but I'm not sure about these things. Please could someone point me in the right direction as to what I could do here? Thanks.