added userid to generate barcode button

static/index.html

@@ -59,8 +59,11 @@
 
     <b>Update Barcodes</b>
     <form action="http:///library.dandhost.com/barcodes" method="POST">
-        <button>Generate Barcodes</button>
+        <label for="userid">UserID</label>
+        <input name="userid" id="userid" value="1"><br>
+        <button>Generate Barcodes</button><br>
+
         <br><br>
-        <a href="/static/barcodes.pdf">Barcodes.pdf</a>
     </form>
+    <a href="/static/barcodes.pdf">Barcodes.pdf</a>
 </div>