Javascript ile butona tıklayınca resmi silmek ve geri gitmek

<script type="text/javascript">
	
	function kapatbuton(){

		<?php unlink($_SESSION['yol2']); ?>

		javascript:history.go(-1);

	}

</script>

<form action="" method="post">
	
	<input type="button" value="+" style="position: absolute;top: 100px;left: 725px;">
	<input type="button" value="Add to cart" style="position: absolute;top: 235px;left: 600px;">
	<input type="button" value="Buy Now!" style="position: absolute;top: 235px;left: 700px;">
	<input type="button" name="kapat" onclick="kapatbuton()" value="Kapat" style="position: absolute;top: 600px;left: 750px;">

</form>