diff --git a/js/validation.js b/js/validation.js
new file mode 100644
index 0000000..521962a
--- /dev/null
+++ b/js/validation.js
@@ -0,0 +1,47 @@
+const validation = new JustValidate("#signup");
+
+validation
+    .addField("#name", [
+        {
+            rule: "required"
+        }
+    ])
+    .addField("#email", [
+        {
+            rule: "required"
+        },
+        {
+            rule: "email"
+        },
+        {
+            validator: (value) => () => {
+                return fetch("validate-email.php?email=" + encodeURIComponent(value))
+                       .then(function(response) {
+                           return response.json();
+                       })
+                       .then(function(json) {
+                           return json.available;
+                       });
+            },
+            errorMessage: "email already taken"
+        }
+    ])
+    .addField("#password", [
+        {
+            rule: "required"
+        },
+        {
+            rule: "password"
+        }
+    ])
+    .addField("#password_confirmation", [
+        {
+            validator: (value, fields) => {
+                return value === fields["#password"].elem.value;
+            },
+            errorMessage: "Passwords should match"
+        }
+    ])
+    .onSuccess((event) => {
+        document.getElementById("signup").submit();
+    });