wordpress match sidebar and body height

matchsidebar.js

//This will match the pages content height if the sidebar is bigger.
getSidebarHeight();
function getSidebarHeight(){
  var sidebar = document.getElementById('sidebar_inner');//<- Sidebar ID
  var sidebarHeight = sidebar.offsetHeight;
  var body = document.getElementById('postBody'); //<- Body ID
  var contentHeight = body.offsetHeight;
  var sidebarHeightPixels = sidebarHeight + "px";

  if(contentHeight < sidebarHeight){
    document.getElementById('postBody').style.minHeight = sidebarHeightPixels;
  }
}