var tabs = new Array('tab1', 'tab2', 'tab3');

window.onload = function() {
    showTab(0);
}

function showTab(iTabIndex) {
    for (counter = 0; counter < tabs.length; counter++) {
        var currentTab = document.getElementById(tabs[counter]);
        var currentHeading = document.getElementById('heading' + counter);

        if (counter == iTabIndex) {
            currentTab.style.display = 'inline';
            currentHeading.className = 'RacingCalendarHeadingLink-Active';
        }
        else {
            currentTab.style.display = 'none';
            currentHeading.className = 'RacingCalendarHeadingLink';
        }
    }
}