Error: Site ID and/or Mobile number not provided
<script>
var selectElement = document.getElementById("class_selection");

if (selectElement) {
    var selectedIndex = selectElement.selectedIndex;
    var selectedOptionText = selectElement.options[selectedIndex].innerText;
    console.log("Selected Class on Load:", selectedOptionText);
}
// Note: The function updateClassSelection() for filtering the classes 
// based on the selected branch must be defined elsewhere in your frontend code.
</script>