diff --git a/src/main/scala/util/ControlUtil.scala b/src/main/scala/util/ControlUtil.scala
index 02d7fd1..af8db88 100644
--- a/src/main/scala/util/ControlUtil.scala
+++ b/src/main/scala/util/ControlUtil.scala
@@ -3,7 +3,7 @@
 import org.eclipse.jgit.api.Git
 import org.eclipse.jgit.revwalk.RevWalk
 import org.eclipse.jgit.treewalk.TreeWalk
-import org.eclipse.jgit.transport.RefSpec
+import scala.util.control.Exception._
 import scala.language.reflectiveCalls
 
 /**
@@ -16,10 +16,8 @@
   def using[A <% { def close(): Unit }, B](resource: A)(f: A => B): B =
     try f(resource) finally {
       if(resource != null){
-        try {
+        allCatch {
           resource.close()
-        } catch {
-          case e: Throwable => // ignore
         }
       }
     }
diff --git a/src/main/scala/util/Implicits.scala b/src/main/scala/util/Implicits.scala
index a9e648c..77c095e 100644
--- a/src/main/scala/util/Implicits.scala
+++ b/src/main/scala/util/Implicits.scala
@@ -1,6 +1,7 @@
 package util
 
 import scala.util.matching.Regex
+import scala.util.control.Exception._
 import javax.servlet.http.{HttpSession, HttpServletRequest}
 
 /**
@@ -42,10 +43,8 @@
       sb.toString
     }
 
-    def toIntOpt: Option[Int] = try {
-      Option(Integer.parseInt(value))
-    } catch {
-      case e: NumberFormatException => None
+    def toIntOpt: Option[Int] = catching(classOf[NumberFormatException]) opt {
+      Integer.parseInt(value)
     }
   }
 
diff --git a/src/main/scala/util/Keys.scala b/src/main/scala/util/Keys.scala
index 4aabe35..920dfca 100644
--- a/src/main/scala/util/Keys.scala
+++ b/src/main/scala/util/Keys.scala
@@ -13,12 +13,7 @@
     /**
      * Session key for the logged in account information.
      */
-    val LoginAccount = "LOGIN_ACCOUNT"
-
-    /**
-     * Session key for the redirect URL.
-     */
-    val Redirect = "REDIRECT"
+    val LoginAccount = "loginAccount"
 
     /**
      * Session key for the issue search condition in dashboard.
@@ -47,6 +42,20 @@
 
   }
 
+  object Flash {
+
+    /**
+     * Flash key for the redirect URL.
+     */
+    val Redirect = "redirect"
+
+    /**
+     * Flash key for the information message.
+     */
+    val Info = "info"
+
+  }
+
   /**
    * Define request keys.
    */