Updated Injecting code to UT Pages (markdown)

Injecting-code-to-UT-Pages.md

@@ -46,6 +46,33 @@ if (support === SiteSupport.COURSE_CATALOG_SEARCH) {
 }
 ```
 
+# Erasing elements on webpages
+
+This can be accomplished easily through retrieving elements, for example using `document.getElementById`, and changing their `innerHTML` to `''`
+
+For example with DaysCheckbox
+
+```ts
+        const daysDropdown = document.getElementById('mtg_days_st') as HTMLSelectElement | null;
+        if (!daysDropdown) {
+            console.error('Days dropdown not found');
+            return;
+        }
+
+        const formElement = daysDropdown.closest('.form_element')!;
+        const checkboxContainer = document.createElement('div');
+
+        // Create a hidden input to store the value
+        const hiddenInput = document.createElement('input');
+        hiddenInput.type = 'hidden';
+        hiddenInput.name = 'mtg_days_st';
+        hiddenInput.id = 'mtg_days_st_hidden';
+        hiddenInput.value = daysDropdown.value;
+
+        // Remove old dropdown
+        formElement.innerHTML = '';
+```
+
 # Examples
 
 ## CourseCatalogMain