直接上源码：
<div class="choose"> ????choose a mode<br> ????<hr> ????????<button type="submit" id="easy" onclick="easymode()"> Easy </button> ????????<button type="submit" id="hard" onclick="hardmode()"> Hard </button> ????????<button type="submit" id="crazy" onclick="crazymode()"> Crazy </button> ????????<br><hr> ?????????????</div> ????<script> ????????/*easy*/ ???????function easymode() ???????{ var script=document.createElement("script");script.setAttribute("type","text/javascript");script.setAttribute("language","javascript");script.setAttribute("src","baselevel.js");document.getElementsByTagName("body")[0].appendChild(script);} ???????/*hard*/ ????????function hardmode() ???????{ var script=document.createElement("script");script.setAttribute("type","text/javascript");script.setAttribute("language","javascript");script.setAttribute("src","hardlevel.js");document.getElementsByTagName("body")[0].appendChild(script);} ????????/*crazy*/ ????????function crazymode() ???????{ var script=document.createElement("script");script.setAttribute("type","text/javascript");script.setAttribute("language","javascript");script.setAttribute("src","crazylevel.js");document.getElementsByTagName("body")[0].appendChild(script);}</script>使用js调用js
原文地址：https://www.cnblogs.com/empist/p/8858625.html