XSTL中单引号的问题

<input type="button" value="确定" style="display:none" id="ok" onclick="return _doClick('48256DE8002DB250.98e6b743dd9b91b248256e11002ebedb/$Body/0.3156', this, null)" />

需要在xslt中读取48256DE8002DB250.98e6b743dd9b91b248256e11002ebedb/$Body/0.3156

<input type="hidden" name="__Click" value='{substring-before(substring-after(//input[@type="button"]/@onclick,"&apos;"),"&apos;")}'/>