Paper IDs have upto but not exactly 4 digits

Change-Id: I45f5d96fb160db98fdb13170c15e75fd17635ceb
diff --git a/templates/register.htm b/templates/register.htm
index c9abd28..3020b4d 100644
--- a/templates/register.htm
+++ b/templates/register.htm
@@ -451,10 +451,10 @@
 
     <div class="form-outline col-md-5">
         <label class="form-label fw-bold" for="paper_id">Paper ID</label>
-        <input type="text" class="form-control fs-4" name="accepted_paper_id" id="paper_id" <?php echo isset($_POST[ 'author']) ? 'placeholder="0000"' : 'disabled' ?> value="
+        <input type="text" class="form-control fs-4" name="accepted_paper_id" id="paper_id" <?php echo isset($_POST[ 'author']) ? 'placeholder="0"' : 'disabled' ?> value="
         <?php echo isset($_POST['paper_id']) ? htmlspecialchars($_POST['paper_id']) : '' ?>" />
         <div class="invalid-feedback">
-            Please provide the 4 digits ID of your accepted paper.
+            Please provide the ID number of your accepted paper.
         </div>
     </div>