<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<style>
#gDiv { width:150px; margin-top:250px; position:fixed;}
#gMsj {width:500px; margin-top:250px; margin-left:auto; margin-right:auto; display:none;}
</style>
<div id="gDiv"><button id="gBtn">Mesajı Göster</button></div>
<div id="gMsj"><img src="resimadresi.jpg" alt="" border="0" />fdsf</div>
<script type="text/javascript">
$("#gBtn").click(function(){
       $("#gMsj").fadeIn("slow");
});
</script>