function getPaySign(appId, timeStamp, nonceStr, package) {
var stringA = 'appId=' + appId +
'&nonceStr=' + nonceStr +
'&package=' + package +
'&signType=MD5' +
'&timeStamp=' + timeStamp
var stringSignTemp = stringA + '&key=' + PAY_API_KEY
var sign = md5(stringSignTemp).toUpperCase()
return sign
}