Dragstart

<div id="dialog"></div>
<script>
$("#dialog").kendoWindow({
  dragstart: function() {
    // the user has started dragging the Window
  }
});
</script>

<div id="dialog"></div>
<script>
function window_dragstart() {
  // the user has started dragging the Window
}
$("#dialog").kendoWindow();
var dialog = $("#dialog").data("kendoWindow");
dialog.bind("dragstart", window_dragstart);
</script>