diff --git a/html/vlan_sub.js b/html/vlan_sub.js
new file mode 100644
index 0000000..ee381de
--- /dev/null
+++ b/html/vlan_sub.js
@@ -0,0 +1,27 @@
+async function vlanSub() {
+  var cmd = "vlan ";
+  var v=document.getElementById('vid').value
+  if (!v) {
+    alert("Set VLAN ID first");
+    return;
+  }
+  cmd = cmd + v;
+  if (document.getElementById('vname').value)
+    cmd = cmd + ' ' + document.getElementById('vname').value;
+  for (let i = 1; i <= numPorts; i++) {
+    if (document.getElementById('tport' + i).checked)
+      cmd = cmd + ` ${i}t`;
+    else if (document.getElementById('uport' + i).checked)
+      cmd = cmd + ` ${i}`;
+  }
+  try {
+    const response = await fetch('/cmd', {
+      method: 'POST',
+      body: cmd
+    });
+    console.log('Completed!', response);
+  } catch(err) {
+    console.error(`Error: ${err}`);
+  }
+}
+