 <p>You may want to use a different event that satisfies your condition:</p> <p>SplitContainer Class: <a href="http://msdn.microsoft.com/en-us/library/system.windows.forms.splitcontainer(v=vs.110).aspx" rel="nofollow">MSDN</a> SplitContainer Event: <a href="http://msdn.microsoft.com/en-us/library/system.windows.forms.control.onmouseclick(v=vs.110).aspx" rel="nofollow">OnMouseClick</a></p> <p>try subscribing to that event if you want it to be fired on click only, also, if you want to unsubscribe to an event, use the <strong>-=</strong> tag.</p>