function Delete_Cookie(name) {
    document.cookie = name +'=; expires=Thu, 01-Jan-70 00:00:01 GMT;';
} 

// this function gets the cookie, if it exists
// don't use this, it's weak and does not handle some cases
// correctly, this is just to maintain legacy information
function Get_Cookie( name ) {

var start = document.cookie.indexOf( name + "=" );
var len = start + name.length + 1;
if ( ( !start ) &&
( name != document.cookie.substring( 0, name.length ) ) )
{
return null;
}
if ( start == -1 ) return null;
var end = document.cookie.indexOf( ";", len );
if ( end == -1 ) end = document.cookie.length;
return unescape( document.cookie.substring( len, end ) );
}