window.navagator.userAgent
let ua = window.navagator.userAgent
let isIE = ua.indexOf('compatible') > -1 && ua.indexOf('MSIE') > -1
let isIE11 = ua.indexOf('Trident') > -1 && ua.indexOf('rv:11.0') > -1
let isFirefox= ua.indexOf('Firefox') > -1
let isChrome= ua.indexOf('Chrome') > -1
let isOpera= ua.indexOf('Opera') > -1
let isSafari= ua.indexOf('Safari') > -1