add error handling

src/components/custom/LeadForm.astro

@@ -92,3 +92,33 @@ let username = "user2s";
     </div>
   </div>
 </form>
+
+<script is:inline>
+  document.getElementById('contact-form').addEventListener('submit', async function(event) {
+    event.preventDefault(); // Prevent the default form submission
+
+    const form = event.target;
+    const formData = new FormData(form);
+    const errorDiv = document.querySelector('.error');
+
+    try {
+      const response = await fetch(form.action, {
+        method: form.method,
+        body: formData
+      });
+
+      if (response.ok) {
+        const result = await response.json();
+        errorDiv.textContent = 'Message sent successfully!';
+        errorDiv.style.color = 'green';
+      } else {
+        const error = await response.json();
+        errorDiv.textContent = `Error: ${error.message}`;
+        errorDiv.style.color = 'red';
+      }
+    } catch (error) {
+      errorDiv.textContent = `Error: ${error.message}`;
+      errorDiv.style.color = 'red';
+    }
+  });
+</script>