Page immediately refreshes itself wiping out my jQuery changes.

Page immediately refreshes itself wiping out my jQuery changes.

I have written code that looks like this. The code works great for about a split second and then the page refreshes itself and I am back to square one. How can I prevent the page from refreshing itself and wiping out my jQuery changes. The page I am working on is located here http://www.sepsserver.com/unvolado/

Thank you!

[code]
<script type="text/javascript" src="jquery-1.5.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$('#youtube').attr({src: '<?php echo $yturl ?>'});

$('#readmore').click(function() {
$('.divheshe:eq(0)').attr({style: 'height: 400px; overflow: hidden;'});
$('.divheshesmall:eq(0)').attr({style: 'float: left; margin-left: 150px; height: 398px; overflow-y: scroll;'});
$('.divheshesmall:eq(1)').attr({style: 'float: right; margin-right: 150px; height: 398px; overflow-y: scroll;'});
});

$('#readmore2').click(function() {
$('.divheshe:eq(0)').attr({style: 'height: 400px; overflow: hidden;'});
$('.divheshesmall:eq(0)').attr({style: 'float: left; margin-left: 150px; height: 398px; overflow-y: scroll;'});
$('.divheshesmall:eq(1)').attr({style: 'float: right; margin-right: 150px; height: 398px; overflow-y: scroll;'});
});

});
</script>
[/code]