button click event required an extra logic gate

src/email.js

@@ -15,7 +15,8 @@ process.nextTick(function() {
 
     document
       .getElementById("signup-form")
-      .addEventListener("click", function() {
+      .addEventListener("click", function(e) {
+        if (e.srcElement.nodeName === 'BUTTON') {
           if (input_email && input_email.value) {
             var is_valid = check_email(input_email.value)
             if (is_valid) {
@@ -23,7 +24,8 @@ process.nextTick(function() {
               form.submit()
             } else {
               input_email.value = ''
-            alert("that doesn't look like an email address, please try again...")
+              alert("that doesn't look like an email address,\nplease try again...")
+            }
           }
         }
       })