[AndrewGSW]

I'm not sure what you are asking: is there a problem with your code, or is there something additional you are trying to achieve?

I notice this code in your first post:

document.cookie="Vln=" + this.value;

This creates a cookie but doesn't set an expiration, so it will be deleted when the browser is closed. Perhaps this is your issue(?).

In which case you probably want a function to set a cookie:

function setCookie( name, value, expires, path, domain, secure ) {
    // Sets the name/value pair - 'expires' is the number of days.
    var expires_date;
    if (expires) {
        expires_date = new Date();
        expires_date.setDate(expires_date.getDate() + expires);
    }
    document.cookie = name + "=" + value +
        ( ( expires ) ? ";expires=" + expires_date.toUTCString() : "" ) +
        ( ( path ) ? ";path=" + path : "" ) +
        ( ( domain ) ? ";domain=" + domain : "" ) +
        ( ( secure ) ? ";secure" : "" );
}