如何使用 amchary URL 传递 javascript 变量

 function custom(vall)
 {
   var chart;

  // create chart
   AmCharts.ready(function() {
    alert(vall);
  // load the data
 var chartData =   AmCharts.loadJSON('http://localhost/vivek/daydata.php?data=vall');                                                   
  // SERIAL CHART    
 chart = new AmCharts.AmSerialChart();
 chart.pathToImages = "http://www.amcharts.com/lib/images/";
 chart.dataProvider = chartData;
chart.categoryField = "hrs";
 chart.theme = "none";
 chart.type = "serial";
}

var chartData = AmCharts.loadJSON('http：//localhost/vivek/daydata.php？date=vall'(;我想在这个 URL 中传递 vall，但它不是取值，在 url 中只显示 vall 变量而不是值。