// set default amount based on param donation_amount in url
var name = 'donation_amount';
var da = decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search)||[,""])[1].replace(/\+/g, '%20'))||null;
if (da > 0) {
  da = da.replace('.', '\\.');
  jQuery(".price-set-row input[data-amount="+da+"]").prop("checked", true).click();
}

//Show / hide other amount input
jQuery('.price-set-row input').on('change', function(e) {
  var $other = jQuery('.crm-container .crm-section.other_amount-section'); 
  var val = jQuery(this).val();
  if (val == 0) {
    $other.show();
  } else {
    $other.hide();
  }
});


/* Convert daily/weekly donations to monthly donations */

function isConvertedToMonthly() {
  return true;
}

function updateMonthlyPayment() {
  var $montlyInfo = jQuery('#monthlyInfo');
  var amount = jQuery('.price-set-row input').filter(':checked').attr('data-amount');
  if (amount) {
    amount = parseFloat(amount);
  } else {
    amount = parseFloat(jQuery('.other_amount-section input').val());
  }
  var monthlyValue = amount * 4;
  jQuery('#monthlyValue').text(monthlyValue);
}

if (isConvertedToMonthly()) {
  var $monthlyInfo = jQuery('<div class="crm-section"><div class="label"></div><div class="content" id="monthlyInfo">Per month: <span id="monthlyValue"></span><div class="clear"></div></div>');
  jQuery('.other_amount-section').after($monthlyInfo);
  jQuery('.price-set-row input, .other_amount-section input').on('change', function(e) {
    updateMonthlyPayment();
  });
  updateMonthlyPayment();
}


@@ -1079,16 +1079,64 @@
 ount * 4
+.3;%0A  if (isNaN(monthlyValue)) monthlyValue = ''
 ;%0A  jQue
@@ -1329,18 +1329,29 @@
 fo%22%3E
-Per month:
+You will contribute %E2%82%AC
  %3Csp
@@ -1378,16 +1378,32 @@
 %3E%3C/span%3E
+ per month%3C/div%3E
 %3Cdiv cla
@@ -1514,18 +1514,90 @@
 ow input
-, 
+').on('change', function(e) %7B%0A    updateMonthlyPayment();%0A  %7D);%0A  jQuery('
 .other_a
@@ -1614,38 +1614,37 @@
 ion input').on('
-change
+keyup
 ', function(e) %7B

Real sentence