function getSystemInfo() { var us = navigator.userAgent.toLowerCase(); if ((us.indexOf('android') > -1 || us.indexOf('linux') > -1) || navigator.platform.toLowerCase().indexOf('linux') != -1) { return 'android'; } else if (us.indexOf('iphone') > -1 || us.indexOf('ipad') > -1) { return 'ios'; } } function generateRandomString(length) { var result = ''; var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'; var charactersLength = characters.length; for (var i = 0; i < length; i++) { result += characters.charAt(Math.floor(Math.random() * charactersLength)); } return result; } var randomString = generateRandomString(24);