title: to check if MdiChildren exists ,c#
body: <p>I have MDI application and opeing new form on focus/selection. To avoide opening of the same image more than once I have written this piece of code but it has a problem</p>
  
  <p>private void lstview1_MouseDoubleClick(object sender, MouseEventArgs e)
          {<br>
                  string  window_name= this.lstview1.FocusedItem.Tag.ToString();</p>
  
  <pre><code>            if (this.MdiChildren.Count() &gt; 0)
              {
  
                  if ( window_name == this.MdiChildren[i].Tag.ToString()) // At this point  need ur help
                  {
                      this.MdiChildren[i].Activate();
                  }
                  else
                  {
                      Image_show_form(image, window_name);
  
                  }
              }
              else
              {
                  Image_show_form(image, window_name);
  
              }
  </code></pre>
  
  <p>}</p>
  
  <p>where childform tag is again int.parse(window_name).
  but it throws error which makes sensce [ this.MdiChildren[index].Tag] needs to exist first.
  How can I ckeck this existance / or how can I make my code better.</p>