A script to make the jquery-ui dialog Responsive.

jquery.custom.fluiddialog.js

/*!
 * Custom script to make jquery-ui dialog responsive.
 * http://stackoverflow.com/a/16471891/413538
 */
(function ($) {

  "use strict";

  function fluidDialog() {
    var $visible = $(".ui-dialog:visible");
    // Each open dialog
    $visible.each(function () {
      var $this = $(this);
      var dialog = $this.find(".ui-dialog-content").data("ui-dialog");
      var wWidth = $(window).width();
      // Check window width against dialog width.
      if (wWidth < (parseInt(dialog.options.maxWidth, 10) + 50)) {
        // Keep dialog from filling entire screen
        $this.css("max-width", "90%");
        $this.css("width", "auto");
      } else {
        // Fix maxWidth bug.
        $this.css("max-width", dialog.options.maxWidth + "px");
      }
      // Reposition dialog.
      dialog.option("position", dialog.options.position);
    });
  }

// Resize dialog on window resize.
  $(window).resize(function () {
    fluidDialog();
  });

// Resize dialog if opened in a viewport smaller than dialog width.
  $(document).on("dialogopen", ".ui-dialog", function () {
    fluidDialog();
  });
})(jQuery);