Autoplay video on first visit

<script language="Javascript">
function played(){
        var ca = document.cookie.split(';');
        for(var i=0; i<ca.length; i++) {
                var c = ca[i];
                while (c.charAt(0)==' ') c = c.substring(1,c.length);
                if (c.indexOf("played=") == 0) return 1;
        }
        var date = new Date();
        var days = 7;
        date.setTime(date.getTime()+(days*24*60*60*1000));
        document.cookie = "played=1"+"; expires="+date.toGMTString()+"; path=/";
        return 0;
}
if(played()==0){
        document.write("<iframe src=\"http://player.vimeo.com/video/(put vimeo id here)?title=0&amp;byline=0&amp;portrait=0&amp;autoplay=1\"  frameborder=\"0\" width=\"420\" height=\"236\" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe>");
}
else{
        document.write("<iframe src=\"http://player.vimeo.com/video/(put vimeo id here)?title=0&amp;byline=0&amp;portrait=0&amp;autoplay=0\" frameborder=\"0\" width=\"420\" height=\"236\" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe>");
}
</script>