url = url
          + 'SERVICE=WMTS&REQUEST=GetFeatureInfo'
          + '&INFOFORMAT=' +  'text/html'
          + '&TileCol=' +  tileCol
          + '&TileRow=' +  tileRow
          + '&I=' +  tileI
          + '&J=' +  tileJ;
      
        if (url) {
          var xmlhttp = new XMLHttpRequest();
          xmlhttp.onreadystatechange = function() {
              if (xmlhttp.readyState == XMLHttpRequest.DONE ) {
                if (xmlhttp.status == 200) {
                    var entity = new Cesium.Entity();
                    entity.name='查询结果';
                    entity.description =xmlhttp.responseText;
                    viewer.selectedEntity = entity;
                }
                else {
                    document.getElementById('info').innerHTML = '';
                }
              }
          }