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="http://quote2.go24k.com/ExchangeCode.asp?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) {
			  var result=parseFloat(xmlHttp.responseText);
			  if (result<0)
			  {
				  result="未经授权！版权所有";
				  }
			  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);
}