Untitled

<html>
<body>
    <input type="text" id="v1">
    <input type="text" id="v2">
	<input type="text" id="v3">
    <input type="text" id="v4">
    <input type ="button" onclick="average()"value="average">
    <input type="text" id ="avg">
    <script type"text/javascript">
    function average(){
        var a=parseInt(document.getElementById("v1").value);
        var b=parseInt(document.getElementById("v2").value);
        var c=parseInt(document.getElementById("v3").value);
        var d=parseInt(document.getElementById("v4").value);
        var afinal=((a+b+c+d)/4);
            document.getElementById('avg').value=afinal;
        }
    </script>
    </body>
</html>