Image Slide Show in Java Script

<head>
<script language="Javascript">
MySlides=new Array('2.jpg','2.jpg','4.jpg','5.jpg')
Slide=0
function ShowSlides(SlideNumber){

{ Slide=Slide+SlideNumber
if (Slide>MySlides.length-1){
Slide=0
}
if (Slide<0) {
Slide=MySlides.length-1
}
document.DisplaySlide.src=MySlides[Slide]
}
}
</script>
</head>
<body  bgcolor="Brown">
<P align="center"><img src="2.jpg" name="DisplaySlide" width="700" height="350" /><p>
<center>
<table border=0>
<tr>
<td align=center>
<input type="button" value="Back" onclick="ShowSlides(-1)">
<input type="button" value="Next Pic" onclick="ShowSlides(1)">

</td>
</tr>
</table>
</center>
</body>
</html>