Snippet for a div to be 100% - 100px of browser window height

100browserheight.js

$(document).ready(function() {
  // for a div to be 100% - 100px of browser window height
    var windowheight = $(window).height();
    var newheight = windowheight - 100;
    $("#landing-section").height(newheight);
});
// with window resize
$(window).resize(function() {
    var windowheight = $(window).height();
    var newheight = windowheight - 100;
    $("#landing-section").height(newheight);
});