SplitterBarPositionChanged Property (SplitterClientEvents)

// The client side event SplitterBarPositionChanged takes two parameters, sender and e.
// Sender is the object which is raising the event
// e is the SplitterBarPositionEventArgs
function WebSplitter1_SplitterBarPositionChanged(sender, e) {
   var websplitter = $find("WebSplitter1");

   // Previous pane is left of hoizontal splitter or above vertical splitter
   // Get new size of previous pane.
   var newSizePrevPane = e.get_prevPaneNewSize();

   // Get old size of previous pane
   var oldSizePrevPane = e.get_prevPaneOldSize();

   // Next pane is right of hoizontal splitter or below vertical splitter
   // Get new size of next pane
   var newSizeNextPane = e.get_nextPaneNewSize();

   // Get old size of next pane
   var oldSizeNextPane = e.get_nextPaneOldSize();

   // Get the orientation of the websplitter, 0 is horizontal, 1 is vertical
   var orientation = websplitter.get_orientation();

   // Checking if orientation is horizontal
   if (orientation == "0") {
     // Checking if next pane was increased
     if (newSizeNextPane >; oldSizeNextPane)
        alert("You have increased the pane size on the right side of the 
               splitter bar");
     else
        alert("You have decreased the pane size on the right side of the 
               splitter bar");
    }
    // Vertical Splitter
    else {
      // Checking of next pane was increased
      if (newSizeNextPane > oldSizeNextPane)
         alert("You have increased the pane size below the splitter bar");
      else
         alert("You have decreased the pane size below the splitter bar");
    }
}