// retrieve site notes

function displaySiteNotes( _site ) {
  var xhttp;

  // build parameters list
  var params = {
    site      : _site,
    }
  
  if ( _site.length > 0 ) {
  
    // async call to php
    xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
      if (this.readyState == 4 && this.status == 200) {

        try {
        
          // parse json formatted response
          var data = JSON.parse(this.responseText);
          
          if ( data.length > 0 ) {

            for (var i in data) {

              // pre-processing ( deviation determination )
              data[i][0]  // notes
              data[i][1]  // height

            }

        }catch(e) {
          //alert(e);
        }


      }
    };
    xhttp.open("GET", "./siteNotes.php" + formatParams(params), true);
    xhttp.send();
  }


}