instead of clearing, highlight said

src/public/index.html

@@ -127,7 +127,7 @@
 
                     ws.send(data);
                     print("SENT: " + input.value);
-                    input.value = "";
+                    input.select();
                     if (document.getElementById("listen").checked) {
                         ws.onmessage({data: data});
                     }