求高手帮忙看一下~关于网页加密的!

<script>l1ll="function ";lll1="x(y)\n";ll1l="{\n";l11l="m=y.split(',');\nvar e='';\n";l111="for(i=0;i<m.length;i++)\n";llll="s=";llll1="String.fromCharCode(";lll1l="m-i-361";ll1ll=");\ne+=s;\n";l1lll="e=e.";lllll="substring(0,e.length-1);\n";ll="return e;\n";l1l1="}";eval(l1ll+lll1+ll1l+l11l+l111+ll1l+llll+llll1+lll1l+ll1ll+l1l1+l1lll+lllll+ll+l1l1);xx="421,409,479,464,427,426,440,438,451,435,448,441,405,472,486,490,477,479,493,441,429,414,492,481,499,489,492,498,476,495,491,508,497,455,443,428,499,512,496,509,502,485,515,501,504,511,517,511,470,458,443,521,510,528,518,521,527,490,520,525,524,526,539,485,473,458,542,542,528,491,535,548,549,546,493,483,484,535,488,486,496,490,541,542,491,545,558,557,496,547,567,568,550,553,559,565,558,568,575,575,508,511,510,514,584,585,586,515,571,581,585,589,582,579,575,571,529,533,528,530,535,529,580,535,584,543,542,541,590,544,540,541,550,550,546,546,594,550,549,601,602,600,556,561,606,557,559,556,558,567,564,610,564,611,564,565,571,566,573,572,573,570,578,572,571,630,643,637,561,632,645,629,642,635,601,647,651,638,640,654,602,590,575,663,650,646,663,652,610,599,599,600,590,586,670,655,671,669,667,668,666,672,666,625,675,677,599,672,670,675,674,676,689,635,625,629,630,640,639,627,654,652,665,649,662,655,649,";document.write(x(xx))

这种的加密 怎么弄? 请大大指导一下 谢谢拉~