add: if (event && event.shiftKey) { numPages = -1; command = "cmd_previousUnreadMsg"; } else { numPages = 1; command = "cmd_nextUnreadMsg"; }  contentWindow.scrollByPages(numPages);   
context: function SpaceHit(){  var contentWindow = window.top._content;  var oldScrollY = contentWindow.scrollY;  contentWindow.scrollByPages(1);  // if at the end of the message, go to the next one  if (oldScrollY == contentWindow.scrollY) {    goDoCommand('cmd_nextUnreadMsg');  }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/459f732ae70109bd1c9c9f35edffce649289aec4/mailWindowOverlay.js/clean/mailnews/base/resources/content/mailWindowOverlay.js