jQuery with ASP.NET selected index changed

Recently I had the need to handle the selected index changed event in an ASP.NET page.  I did not want to post back to the server as I just wanted to hide/show an HTML element, so jQuery was the perfect fit.

Below is the code.  Basically, within the jQuery document ready funciton, I wire a function to each dropdown list ('select') change event.  You will probably want to refine this to a single id or class.  Each time the dropdown selected index changes, I want to check the text value, and if it contains some text, either show or hide an HTML element.  I also set a checkbox control to checked using the client id within a script tag.

<script type="text/javascript">

$(function() {

$('select').change(function(e) {

if (this[this.selectedIndex].text.indexOf("SomeText") > 0) { $('#emailActivity').fadeIn("slow");

// Ensure checkbox initially checked

$('#<%=cbSendEmail.ClientID %>').attr('checked', true);

}

else {$('#emailActivity').fadeOut();

}

});

});

</script>