微信支付时提示xml格式错误,求解决
<xml>
<appid>wx842b83889bd3</appid>
<attach>1.01</attach>
<body>流量卡充值</body>
<device_info>WEB</device_info>
<fee_type>CNY</fee_type>
<goods_tag>WXG</goods_tag>
<mch_id>1274449601</mch_id>
<nonce_str>1A4I1GQAM0079E672879000031AFA396</nonce_str>
<notify_url>http://www.baidu.com/ss/pay.jsp</notify_url>
<openid>oxljPs4yHqfSNQLvKkDJv_U</openid>
<out_trade_no>1A4I1GQAM0089E6728790000B65592A7</out_trade_no>
<product_id>1A4I1GQAM0099E6728790000E8296BBC</product_id>
<spbill_create_ip>111.40.122.158</spbill_create_ip>
<time_expire>20151120170238</time_expire>
<time_start>20151120165238</time_start>
<total_fee>1.01</total_fee>
<trade_type>JSAPI</trade_type>
<sign>6F984CCDEE90B7C66B95956410620157</sign>
</xml>
返回的是{"xml":{"return_msg":"XML格式错误","return_code":"FAIL"}}