if (this.readyState != 4 || this.status != 200) return;
var returnedData = JSON.parse(this.responseText);
trackName = GetFilename(returnedData['current_playing']);
if (this.readyState != 4 || this.status != 200) return;
var returnedData = JSON.parse(this.responseText);
trackName = GetFilename(returnedData['current_playing']);