diff --git a/pmcalendar.php b/pmcalendar.php
index 6ee6b6f..8f71909 100644
--- a/pmcalendar.php
+++ b/pmcalendar.php
@@ -201,12 +201,13 @@ if ($act == 'newevent') {
     we('1');
 }  else if ($act == 'edityanqi') {
     $id = r('id');
-    $idx = r('idx');
+    $idx = (int)r('idx');
     $del = r('del');
     $content = stripslashes(r('content'));
     $dict = array();
     $event = DB::getone("select yanqi_history from calendar where id={$id}");
-    $yanqi_history = $event['yanqi_history'];
+
+    $yanqi_history = json_decode($event['yanqi_history'],true);
     if(!$del) {
         $yanqi_history[$idx]['reason'] = $content;
     }