title: ProgressBar multiple displaying
body: <p>I have an AsyncTask linked to a refresh Button (when I click on my refresh button my AsyncTask is called).</p>
  
  <p>I have on my Layout a LinearLayout field for my ProgressBar :</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:orientation="vertical"
      android:background="@color/grey"&gt;
       &lt;Button    android:id="@+id/refresh_p"
                  android:text="@string/refresh_promo"
                  android:layout_width="fill_parent"
                  android:layout_height="wrap_content"
                  android:background="@drawable/custom_button1"/&gt;
  
     &lt;LinearLayout android:id="@+id/linearlayoutProgressBar"
                      android:layout_width="fill_parent"
                      android:layout_height="wrap_content"
                      android:gravity="center"/&gt;
     &lt;ListView
          android:id="@android:id/list"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:listSelector="@color/tabTransparent"
          android:cacheColorHint="#00000000"/&gt;
        &lt;!--   &lt;ListView android:id="@+id/list_promo"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"/&gt;--&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>In my AsyncTask :</p>
  
  <pre><code>@Override
      protected void onPreExecute() 
      {
          super.onPreExecute();
  
          pb = new ProgressBar(context);
          LinearLayout ll = (LinearLayout) ((Activity) context).findViewById(R.id.linearlayoutProgressBar);
          ll.addView(pb);
          pb.setVisibility(View.VISIBLE);
      }
  
      @Override
      protected void onPostExecute(ArrayList&lt;HashMap&lt;String, String&gt;&gt; promoList) 
      {
          ...
  
          if (pb!=null) 
          {
              pb.setVisibility(View.GONE);
              ((LinearLayout)pb.getParent()).removeView(pb);
          }
      }
  </code></pre>
  
  <p>The problem I have is when I make more than 2 clicks on my Refresh Button then Multiple ProgressBar are displaying into the screen.. I just want that the new ProgressBar replace the old at the same position ..</p>