diff --git a/static/main.js b/static/main.js
index e381ac6..a07eb52 100644
--- a/static/main.js
+++ b/static/main.js
@@ -2,6 +2,7 @@
 (function () {
     'use strict';
     window.addEventListener('load', function () {
+        update_total_costs();
         // Fetch all the forms we want to apply custom Bootstrap validation styles to
         var forms = document.getElementsByClassName('needs-validation');
         // Loop over them and prevent submission
@@ -17,6 +18,37 @@
     }, false);
 })();
 
+function update_total_costs() {
+    var costs = 0;
+
+
+    if ($('#participate').is(":checked")) {
+        costs += parseInt($("#conference_fee").text(),10);
+        if ($('#student').is(":checked")) {
+            costs -= parseInt($("#student_discount").text(), 10);
+        }
+        if ($('#conference_dinner').is(":checked")) {
+            costs += parseInt($("#conference_dinner_price").text(), 10);
+        }
+    }
+    $("#total_costs").val(costs.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2}));
+}
+
+function update_paper_id_field() {
+    var paper_id = $("#paper_id");
+    if ($('#author').is(":checked")) {
+        paper_id.removeAttr('disabled');
+        paper_id.attr('placeholder', '0000');
+        paper_id.attr('pattern', '\\d{4}');
+        paper_id.attr('required', 'required');
+    } else {
+        paper_id.val('');
+        paper_id.attr('disabled', 'disabled');
+        paper_id.removeAttr('placeholder');
+        paper_id.removeAttr('pattern');
+        paper_id.removeAttr('required');
+    }
+}
 
 function check_password_match() {
     pass = $("#pw1").val();