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var preview_page = "{?$preview_page?}";
var next_page = "{?$next_page?}";
var index_page = "{?$index_page?}";
var article_id = "{?$article_id?}";
var chapter_id = "{?$chapter_id?}";

function jumpPage() {
var event=document.all?window.event:arguments[0];
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document.onkeydown=jumpPage;
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