function hidediv(id) {
    //function to hide an element with a specified id
        document.getElementById(id).style.display = 'none';    
}
function showdiv(id) {
    //function to show an element with a specified id
        document.getElementById(id).style.display = 'block';
}
function showrace(id) {
    //function shows map and details for a race - hides other races
    
    //show race
    document.getElementById('map' + id).style.display = 'block';
    document.getElementById('ride' + id).style.display = 'block';
    document.getElementById('a' + id).style.background = '#CC0000';
        
    //hide races
    var a = 1
    while (a < 6)
    {
        if (a != id)
        {
            document.getElementById('map' + a).style.display = 'none';
            document.getElementById('ride' + a).style.display = 'none';
            document.getElementById('a' + a).style.background = '#999999';
        }
        a = a + 1
    }
    document.getElementById('rideOverview').style.display = 'none';
    document.getElementById('imgOverview').style.display = 'none';
}