The below code snippet explains how to get the Index, Value and Text of last selected option of HTML Multi Select ListBox using jQuery
<select id="mySelect" multiple = "multiple">
    <option value="1">Mango</option>
    <option value="2">Banana</option>
    <option value="3">Grapes</option>
    <option value="4">Guava</option>
    <option value="5">Pineapple</option>
    <option value="6">Apple</option>
    <option value="7">Orange</option>
    <option value="8">Lemon</option>
<input type="button" id="demo" value = "Demo" />
<script type = "text/javascript" src=""></script>
<script type="text/javascript">
    $("#demo").live("click", function () {
        //Get selected option of the HTML SELECT
        var selectedItem = $("#mySelect option:selected").last();
        //Get the value of the selected option
        alert("SelectedItem Value: " + selectedItem.val());
        //Get html or text of the selected option
        alert("SelectedItem Text: " + selectedItem.html());
        //Get index of selected option
        alert("SelectedItem Index: " + selectedItem.index());
The button with ID demo is attached with a click event. When the button is clicked the last selected item of the HTML Multi Select ListBox with ID mySelect is retrieved. Then the Selected Item’s Text, Value and Index is displayed via JavaScript alert.