diff --git a/pages/signup-oauth.tmpl b/pages/signup-oauth.tmpl
index 34081cf..3fd4255 100644
--- a/pages/signup-oauth.tmpl
+++ b/pages/signup-oauth.tmpl
@@ -1,118 +1,180 @@
 {{define "head"}}<title>Log in &mdash; {{.SiteName}}</title>
 <meta name="description" content="Log in to {{.SiteName}}.">
 <meta itemprop="description" content="Log in to {{.SiteName}}.">
 <style>input{margin-bottom:0.5em;}</style>
 <style type="text/css">
 h2 {
 	font-weight: normal;
 }
 #pricing.content-container div.form-container #payment-form {
 	display: block !important;
 }
 #pricing #signup-form table {
 	max-width: inherit !important;
 	width: 100%;
 }
 #pricing #payment-form table {
 	margin-top: 0 !important;
 	max-width: inherit !important;
 	width: 100%;
 }
 tr.subscription {
 	border-spacing: 0;
 }
 #pricing.content-container tr.subscription button {
 	margin-top: 0 !important;
 	margin-bottom: 0 !important;
 	width: 100%;
 }
 #pricing tr.subscription td {
 	padding: 0 0.5em;
 }
 #pricing table.billing > tbody > tr > td:first-child {
 	vertical-align: middle !important;
 }
 .billing-section {
 	display: none;
 }
 .billing-section.bill-me {
 	display: table-row;
 }
 #btn-create {
 	color: white !important;
 }
 #total-price {
 	padding-left: 0.5em;
 }
 #alias-site.demo {
 	color: #999;
 }
 #alias-site {
 	text-align: left;
 	margin: 0.5em 0;
 }
 form dd {
 	margin: 0;
 }
 </style>
 {{end}}
 {{define "content"}}
 <div id="pricing" class="tight content-container">
 	<h1>Log in to {{.SiteName}}</h1>
 
 	{{if .Flashes}}<ul class="errors">
 		{{range .Flashes}}<li class="urgent">{{.}}</li>{{end}}
 	</ul>{{end}}
 
     <div id="billing">
-	    <form action="/oauth/signup" method="post" style="text-align: center;margin-top:1em;" onsubmit="disableSubmit()">
+	    <form action="/oauth/signup" method="post" style="text-align: center;margin-top:1em;" onsubmit="return disableSubmit()">
 	        <input type="hidden" name="access_token" value="{{ .AccessToken }}" />
 	        <input type="hidden" name="token_username" value="{{ .TokenUsername }}" />
 	        <input type="hidden" name="token_alias" value="{{ .TokenAlias }}" />
 	        <input type="hidden" name="token_email" value="{{ .TokenEmail }}" />
 	        <input type="hidden" name="token_remote_user" value="{{ .TokenRemoteUser }}" />
 	        <input type="hidden" name="provider" value="{{ .Provider }}" />
 	        <input type="hidden" name="client_id" value="{{ .ClientID }}" />
 	        <input type="hidden" name="signature" value="{{ .TokenHash }}" />
 
             <dl class="billing">
                 <label>
                     <dt>Blog Title</dt>
                     <dd>
                         <input type="text" style="width: 100%; box-sizing: border-box;" name="alias" placeholder="Alias"{{ if .Alias }} value="{{.Alias}}"{{ end }} />
                     </dd>
                 </label>
                 <label>
                     <dt>Username</dt>
 					<dd>
-		<input type="text" name="username" style="width: 100%; box-sizing: border-box;" placeholder="Username" value="{{.Username}}" /><br />
+		<input type="text" id="username" name="username" style="width: 100%; box-sizing: border-box;" placeholder="Username" value="{{.Username}}" /><br />
 		{{if .Federation}}<p id="alias-site" class="demo">@<strong>your-username</strong>@{{.FriendlyHost}}</p>{{else}}<p id="alias-site" class="demo">{{.FriendlyHost}}/<strong>your-username</strong></p>{{end}}
                     </dd>
                 </label>
                 <label>
                     <dt>Email</dt>
                     <dd>
 <input type="text" name="email" style="width: 100%; box-sizing: border-box;" placeholder="Email"{{ if .Email }} value="{{.Email}}"{{ end }} />
                     </dd>
                 </label>
                 <label>
                     <dt>Password</dt>
                     <dd>
 <input type="password" name="password" style="width: 100%; box-sizing: border-box;" placeholder="Password" /><br />
                     </dd>
                 </label>
                 <dt>
                     <input type="submit" id="btn-login" value="Login" />
                 </dt>
             </dl>
         </form>
     </div>
 
+<script type="text/javascript" src="/js/h.js"></script>
 <script type="text/javascript">
+// Copied from signup.tmpl
+// NOTE: this element is named "alias" on signup.tmpl and "username" here
+var $alias = H.getEl('username');
+
 function disableSubmit() {
+    // Validate input
+    if (!aliasOK) {
+        var $a = $alias;
+        $a.el.className = 'error';
+        $a.el.focus();
+        $a.el.scrollIntoView();
+        return false;
+    }
+
 	var $btn = document.getElementById("btn-login");
 	$btn.value = "Logging in...";
 	$btn.disabled = true;
+	return true;
 }
+
+// Copied from signup.tmpl
+var $aliasSite = document.getElementById('alias-site');
+var aliasOK = true;
+var typingTimer;
+var doneTypingInterval = 750;
+var doneTyping = function() {
+    // Check on username
+    var alias = $alias.el.value;
+    if (alias != "") {
+        var params = {
+            username: alias
+        };
+        var http = new XMLHttpRequest();
+        http.open("POST", '/api/alias', true);
+
+        // Send the proper header information along with the request
+        http.setRequestHeader("Content-type", "application/json");
+
+        http.onreadystatechange = function() {
+            if (http.readyState == 4) {
+                data = JSON.parse(http.responseText);
+                if (http.status == 200) {
+                    aliasOK = true;
+                    $alias.removeClass('error');
+                    $aliasSite.className = $aliasSite.className.replace(/(?:^|\s)demo(?!\S)/g, '');
+                    $aliasSite.className = $aliasSite.className.replace(/(?:^|\s)error(?!\S)/g, '');
+                    $aliasSite.innerHTML = '{{ if .Federation }}@<strong>' + data.data + '</strong>@{{.FriendlyHost}}{{ else }}{{.FriendlyHost}}/<strong>' + data.data + '</strong>/{{ end }}';
+                } else {
+                    aliasOK = false;
+                    $alias.setClass('error');
+                    $aliasSite.className = 'error';
+                    $aliasSite.textContent = data.error_msg;
+                }
+            }
+        }
+        http.send(JSON.stringify(params));
+    } else {
+        $aliasSite.className += ' demo';
+        $aliasSite.innerHTML = '{{ if .Federation }}@<strong>your-username</strong>@{{.FriendlyHost}}{{ else }}{{.FriendlyHost}}/<strong>your-username</strong>/{{ end }}';
+    }
+};
+$alias.on('keyup input', function() {
+    clearTimeout(typingTimer);
+    typingTimer = setTimeout(doneTyping, doneTypingInterval);
+});
+doneTyping();
 </script>
 {{end}}