判断body尺寸加载js文件

(function() {   console.log(document.body.offsetWidth);   if(document.body.offsetWidth > 1900) {      loadJs("../../js/crm-index.js")   } else if (document.body.offsetWidth < 1880) {      loadJs("../../js/crm-index2.js")   }})()function loadJs(src) {   var head = document.getElementsByTagName('head')[0];   var s = document.createElement("script");   s.type = "text/javascript";   s.src = src;   head.appendChild(s);}