Form submit add domain to username field if missing
<p>I have a login form that includes a username and password field. </p>

<p>Users will be able to login using:</p>

<p>Domain\username
And
Username@domain.org.uk</p>

<p>However many users attempt to login using just 'username'</p>

<p>I want to help users by adding domain\ or @domain.org.uk to there username when they enter just 'username', when they click the login button I want to add the domain part of the username.</p>

<p>How can I do this in pure JavaScript?</p>
