C#怎么还原这段js，winform下

<script language='javascript'>
<!--
document.writeln(unescape(unescape('%253Cscript%2520language%253D%2527jav')+'ascript%27%3E%0A%3C'+'%21--%0Adocument.wr'+'iteln%28une'+unescape('scape%2528unescape%2528%2527%2525253C')+'script%252520l'+unescape('ang%2527%252B%2527uage%2525253D%2525')+'2527%27%2Bunescape%28%27JScr'+'ipt.Encode%25252527%27%'+'29%2Bunescape%28'+'%27%2525253E%25252523'+unescape('%2525252540%2527%2529%252Bun')+unescape('escape%2528%2527%252525257E%25252')+unescape('5255ESwA%2527%2529%252Bunescape%2528u')+unescape('nescape%2528%2527AAA')+unescape('%25252525253D%25252525253D-mD%25')+unescape('252525257E%2525252525%2527%252')+'9%29%2B%277FDK%252527B8bZ9'+unescape('Fl%252525%2527%252B%252721%25252529FW')+unescape('%252525%2527%252Bunescape%2528%252721')+'oqy%252525'+'21F8%2525257B%25'+unescape('25252%2527%2529%252B')+unescape('%25271FF%25252526Z%252525')+'24T%25252%27%2B%276Z%25252AZ'+'%252520T%27%2B%27%'+'252521T%25252F8%252521q%2'+unescape('5252C8%2525%2527%252Bunescape%25')+'28unescape%28%27252FF%25'+unescape('2525252BF9TA%25252525')+unescape('2521cq%2527%2529%2529%252')+'Bunescape%28%270Z%25'+unescape('25252Cq28qZ%2525252525T%252')+'525252BF%25252%27%29%'+unescape('2B%252757EFsEiy')+'RAAAA%25253D%2525'+unescape('3D%2525255%2527%252B%252')+'7E%252523%25257E%25%27%2Bun'+unescape('escape%2528%25272540%252525253C%25252')+unescape('5252Fscript%25252')+'5253E%27%29%29%29%29%3'+unescape('B%250A%252F%252F--%253E%250A%253C%252Fs')+unescape('cript%253E')));
//-->
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