var wmsLayer2 = new ol.layer.Image({
  source: wmsSource2
});

$("#Buildings_chkbx").click(function(){
  layers.push("wmsLayer2");
});


var map = new ol.Map({
  target: 'map',
  layers: [baseLayer, wmsLayer],
  view: new ol.View({
    center: ol.proj.fromLonLat([33.33386, 35.14710]),
    zoom: 14
  })
});