diff --git a/source/app/SubWindowHandle.cpp b/source/app/SubWindowHandle.cpp
index 4617c63..401c596 100644
--- a/source/app/SubWindowHandle.cpp
+++ b/source/app/SubWindowHandle.cpp
@@ -176,6 +176,11 @@ Bool SubWindowHandle::save()
   return true;
 }
 
+Void SubWindowHandle::play()
+{
+  m_bIsPlaying = true;
+}
+
 Int SubWindowHandle::playEvent()
 {
   if( m_bIsPlaying )
@@ -209,8 +214,9 @@ Void SubWindowHandle::seekRelativeEvent( Bool bIsFoward )
   refreshFrame();
 }
 
-Void SubWindowHandle::stopEvent()
+Void SubWindowHandle::stop()
 {
+  m_bIsPlaying = false;
   seekAbsoluteEvent( 0 );
   return;
 }
@@ -321,7 +327,12 @@ Bool SubWindowHandle::mayClose()
 
 void SubWindowHandle::closeEvent( QCloseEvent *event )
 {
-  event->accept();
+  Bool bAccept = true;
+  bAccept = m_bIsPlaying ? false : bAccept;
+  if( bAccept )
+    event->accept();
+  else
+    event->ignore();
 }
 
 }  // NAMESPACE
diff --git a/source/app/SubWindowHandle.h b/source/app/SubWindowHandle.h
index 3d38701..154a355 100644
--- a/source/app/SubWindowHandle.h
+++ b/source/app/SubWindowHandle.h
@@ -67,8 +67,9 @@ public:
   Bool loadFile( const QString &fileName );
   Bool save();
 
+  Void play();
   Int playEvent();
-  Void stopEvent();
+  Void stop();
 
   Void seekAbsoluteEvent( UInt new_frame_num );
   Void seekRelativeEvent( Bool bIsFoward );
diff --git a/source/app/plaYUVerApp.cpp b/source/app/plaYUVerApp.cpp
index 676ce13..3c37f83 100644
--- a/source/app/plaYUVerApp.cpp
+++ b/source/app/plaYUVerApp.cpp
@@ -235,6 +235,7 @@ void plaYUVerApp::play()
       {
         m_acPlayingSubWindows.append( m_pcCurrentSubWindow );
         m_pcCurrentSubWindow->seekAbsoluteEvent( m_acPlayingSubWindows.at( 0 )->getInputStream()->getCurrFrameNum() );
+        m_pcCurrentSubWindow->play();
         m_pcFrameSlider->setMaximum( qMin( m_pcFrameSlider->maximum(), ( Int )m_pcCurrentSubWindow->getInputStream()->getFrameNum() - 1 ) );
       }
     }
@@ -243,6 +244,7 @@ void plaYUVerApp::play()
       playingTimer->stop();
       m_acPlayingSubWindows.clear();
       m_acPlayingSubWindows.append( m_pcCurrentSubWindow );
+      m_pcCurrentSubWindow->play();
       m_uiAveragePlayInterval = 0;
       m_bIsPlaying = false;
     }
@@ -270,7 +272,7 @@ void plaYUVerApp::stop()
   {
     for( Int i = 0; i < m_acPlayingSubWindows.size(); i++ )
     {
-      m_acPlayingSubWindows.at( i )->stopEvent();
+      m_acPlayingSubWindows.at( i )->stop();
     }
     m_acPlayingSubWindows.clear();
     playingTimer->stop();
@@ -284,7 +286,7 @@ void plaYUVerApp::stop()
   }
   else
   {
-    m_pcCurrentSubWindow->stopEvent();
+    m_pcCurrentSubWindow->stop();
     playingTimer->stop();
     m_pcFrameSlider->setValue( m_pcCurrentSubWindow->getInputStream()->getCurrFrameNum() );
   }