Behaviour for Jalousie Window

gistfile1.js

var xc, yc;  // X and Y coordinates of the mouse pointer.

// Change perspective origin as the mouse pointer moves.
document.body.addEventListener( 'mousemove', function( event ) {
  // Chrome returns event.x and event.y whereas Firefox returns
  // eventclientX and eventClientY.
  'x' in event ? xc = event.x : xc = event.clientX;
  'y' in event ? yc = event.y : yc = event.clientY;
  document.body.setAttribute('style', 'perspective-origin:' + xc + 'px ' + yc + 'px;' + '-webkit-perspective-origin-x:' + xc + 'px; -webkit-perspective-origin-y:' + yc + 'px' );
});