Cookis in JavaScript

JavaScript Code:

<script language="javascript" type="text/javascript">

    function getCookieValue(offset)

    {

        var endstring = document.cookie.indexOf(";", offset);

        if (endstring == -1)

        {

            endstring = document.cookie.length;

            return unescape(document.cookie.substring(offset, endstring));

        }

    }

    function getcookie(name) {

        var arg = name + ":";

        var strlength = arg.length;

        var cookielength = document.cookie.length;

        var i = 0;

        while (i < cookielength) {

            var j = i + strlength;

            if (document.cookie.substring(i, j) == arg)

            {

                return getCookieValue(j);

                i = document.cookie.indexOf(" ", i) + 1;

            }

            if (i == 0)

            {

                break;

            }

        }

        return null;

    }

    function setcookie(name, value)

    {

        var argv = setcookie.arguments;

        var argc = setcookie.arguments.length;

        var expires = (argc > 2) ? argv[2] : null;

        var path = (argc > 3) ? argv[3] : null;

        var domain = (argc > 4) ? argv[4] : null;

        var secure = (argc > 5) ? argv[5] : false;

        document.cookie = name + "=" + escape(value) +

        ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +

        ((path == null) ? "" : ("; path=" + path)) +

        ((domain == null) ? "" : ("; domain=" + domain)) +

        ((secure == true) ? "; secure" : "");

    }

    function DeleteCookie(name) {

        var exp = new Date();

        exp.setTime(exp.getTime() - 1);

        var cval = getcookie(name);

        document.cookie = name + ":" + cval + "; expires=" + exp.toGMTString();

    }

    function shows() {

        if (getcookie('Demoname') == null)

        {

            alert('Did you submit the request?');

        }

        else

        {

            window.open('open.htm', '_top');

        }

    }

</script>

HTML Code:

 <form name="FormID" onSubmit="

    if(FormID.Username.value.length != 0) {

        var expdate = new Date();

        expdate.setTime(expdate.getTime() + (24 * 60 * 60 * 1000));

        setcookie('FormID', FormID.Username.value, expdate);

        alert('Enter here!!');

        return false;

    } else {

        alert('You left the name field blank!!');

        return false;

    }">

    <input type="text" name="Username" /><br />

    <input type="submit" value="Submit the Request!" /></br>

    <input type="button" value="Enter here!" onClick="this.shows()" />

</form>