add: new js files for simplicity

assets/js/register.js

@@ -10,15 +10,13 @@ registerBtn.addEventListener("click", handleSubmit);
 
 // Function to handle form submission
 function handleSubmit(event) {
-    // Prevent default form submission behavior
-    event.preventDefault();
-
     // Validate input
     const name = nameInput.value;
     const email = emailInput.value;
     const password = passwordInput.value;
 
     if (name === "" || email === "" || password === "") {
+        event.preventDefault();
         alert("Please fill in all fields.");
         return;
     }