Show hidden scrollbar

A client is opening our website into a popup window usin开发者_开发知识库g JavaScript with window.open. They are turning off scrollbars and making the window a fixed height, causing the pages to not be scrollable. I control the code of the website being loaded this way, but not the calling JavaScript. Is there any way I can force the display of scrollbars?

body { overflow: auto }

should bring back the scroll bars. If it doesn't, and the scrollbar directive in fact turns off the body's scroll bars (I don't know right now whether that is the case), add a wrapper DIV in the body:

html, body { height: 100% }

.wrapper {
  width: 100%;
  height: 100%;
  overflow: auto

}


<div class="wrapper"> ......