diff --git a/public/js/gf-giftaid-field-frontend.js b/public/js/gf-giftaid-field-frontend.js
index f215959..01f9801 100644
--- a/public/js/gf-giftaid-field-frontend.js
+++ b/public/js/gf-giftaid-field-frontend.js
@@ -12,16 +12,31 @@ function initGiftAid() {
   if (!totalSelector) {
     return;
   }
-  window.gform.addAction('gform_input_change', function (elem) {
-      const donationValue = parseFloat(elem.value);
+  window.gform.addAction(
+    'gform_input_change',
+    function (elem) {
+      if (
+        !(elem instanceof HTMLInputElement) ||
+        !elem.closest(totalSelector) ||
+        !elem.value
+      ) {
+        return;
+      }
+      const sanitizedValue = elem.value.replace(/[^0-9.]/g, '');
+      const donationValue = parseFloat(sanitizedValue);
       const giftAidValue = donationValue * 1.25;
+      if (!donationValue || !giftAidValue) {
+        return;
+      }
       const donationRounded = donationValue.toFixed(2);
       const giftAidRounded = giftAidValue.toFixed(2);
       if (!donationRounded || !giftAidRounded) {
         return;
       }
       updateGiftAidDisplay(gravityForm, donationRounded, giftAidRounded);
-    }, 10);
+    },
+    10,
+  );
 }
 
 /**
diff --git a/src/GfGiftAidField.php b/src/GfGiftAidField.php
index 86c47da..8937141 100644
--- a/src/GfGiftAidField.php
+++ b/src/GfGiftAidField.php
@@ -23,6 +23,7 @@ public static function run(): void
         GFAddOn::register(AddOn::class);
 
         add_action('gform_field_standard_settings', [static::class, 'addSelectedPriceFieldSetting'], 10, 2);
+        add_action('gform_editor_js', [static::class, 'addSelectedPriceFieldScript']);
     }
 
     /**
@@ -33,10 +34,15 @@ public static function addSelectedPriceFieldSetting(int $position, int $form_id)
         if (25 !== $position || empty($form_id)) {
             return;
         }
+        $exists = GFAPI::form_id_exists($form_id);
+        if (empty($exists)) {
+            return;
+        }
         $field_options = static::getFormFields($form_id);
         if (empty($field_options)) {
             return;
         }
+
         ?>
         <li class="selected_price_field_setting field_setting">
             <label for="selected_price_field_dropdown" class="section_label">
@@ -48,6 +54,8 @@ public static function addSelectedPriceFieldSetting(int $position, int $form_id)
                 id="selected_price_field_dropdown"
                 onchange="SetFieldProperty('selectedPriceField', this.value);"
             >
+                <option value="">--Please select a field--</option>
+
                 <?php foreach ($field_options as $field_id => $field_label) : ?>
                     <?php
                     if (empty($field_id) || empty($field_label)) {
@@ -62,17 +70,37 @@ public static function addSelectedPriceFieldSetting(int $position, int $form_id)
         <?php
     }
 
+    public static function addSelectedPriceFieldScript(): void
+    {
+        ?>
+        <script type='text/javascript'>
+            //adding setting to fields of type "text"
+            fieldSettings.text += ', .selected_price_field_setting';
+            // Update the field settings when the field is loaded in the form editor
+            jQuery(document).on('gform_load_field_settings', function(event, field, form) {
+                if (!field || !field.type || 'gift_aid' !== field.type) {
+                    return;
+                }
+                var savedValue = rgar(field, 'selectedPriceField');
+                if (!savedValue) {
+                    return;
+                }
+                var selectedPriceDropdown = document.querySelector('#selected_price_field_dropdown');
+                if (!(selectedPriceDropdown instanceof HTMLSelectElement)) {
+                    return;
+                }
+                selectedPriceDropdown.value = savedValue;
+            });
+        </script>
+        <?php
+    }
+
     /**
      * Get all the fields in a gravity form in the format:
      * ['field class' => 'field_label', ...]
      */
     public static function getFormFields(int $form_id): array
     {
-        $exists = GFAPI::form_id_exists($form_id);
-        if (empty($exists)) {
-            return [];
-        }
-
         $form = GFAPI::get_form($form_id);
         $fields = $form['fields'] ?? [];
         if (empty($fields) || !is_array($fields)) {