function changed() 
{
    var former_currency=document.all("former_currency")[document.all("former_currency").selectedIndex].value;
    var object_currency=document.all('object_currency')[document.all('object_currency').selectedIndex].value;
    var original_value=document.getElementById("original_value").value;
    var object_value=document.getElementById("object_value").value;
    if (isNaN(original_value))
    {
        alert("温馨提示：原价格只能为数字！\n请检查您的输入法是否是全角状态");
        document.all("original_value").focus();
    }
    else
    {
        var url="quote/exchangeCode.php?former_currency="+former_currency+"&object_currency="+object_currency+"&original_value="+original_value;
        CreateXMLHTTP(url,"object_value")
    }
}

function CreateXMLHTTP(url,DivId)
 {
var xmlHttp = false;
      //判断浏览器
      try {
               xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
             }
       catch (e) {
           try {
                  xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
                 } 
            catch (e2) {
                          xmlHttp = false;
                    }
              }

     if (!xmlHttp && typeof XMLHttpRequest != 'undefined') //判断是不是Firefox浏览等
             {
             xmlHttp = new XMLHttpRequest();
             if (xmlHttp.overrideMimeType) 
                {
                   xmlHttp.overrideMimeType('text/xml');
               }
        }
     xmlHttp.onreadystatechange = function(){
     if (xmlHttp.readyState==1 || xmlHttp.readyState==2 || xmlHttp.readyState==3 )
     {
      document.getElementById(DivId).value="正在计算...";
     }
     if (xmlHttp.readyState == 4) { 
          if (xmlHttp.status==200   ||   xmlHttp.staus==0) {
              var result=parseFloat(xmlHttp.responseText);
              if (result<0)
              {
                  result=" 网站名称 ";
                  }
              document.getElementById(DivId).value =  result;
              }
           }
      }
     xmlHttp.open("get",url,true);    
     xmlHttp.setRequestHeader("Content-Type","text/html");  
     xmlHttp.setRequestHeader("Content-Type","charset=gb2312"); 
     xmlHttp.send(null);
}