Create a simple error message

Hi Thanks for your interest in this bid request. This is a very simple job for anyone with a basic understanding of HTML. Currently, you can just click "go" on my website without entering an email address. This means I get lots of blank registrations. So I want an error message created to prevent this from happening. ## Deliverables More details on the error message: The newsletter signup page is here: [login to view URL] At the bottom right of the page. Here is step by step what I want to happen: 1. A user clicks Go without entering their email address 2. An error message appears that says "The email address you have entered is not in the correct format. Please try again." 3. If the user enters an email address that doesn't inclue the @ sympbol, then they will also see the error message. 4. If they enter a correct email address, they will be taken to this page: [login to view URL] Any questions, please let me know. The page in question will be sent to the successful bidder. Thanks James.