function tab_change_on1() {
    if (document.getElementById('tab1') != null) {
        document.getElementById('tab1').style.backgroundImage = 'url(/images/tab_bg_active_hover.gif)';
    }
}

function tab_change_off1() {
    if (document.getElementById('tab1') != null) {
        document.getElementById('tab1').style.backgroundImage = 'url(/images/tab_bg.gif)';
    }
}

function tab_change_on2() {
    if (document.getElementById('tab2') != null) {
        document.getElementById('tab2').style.backgroundImage = 'url(/images/tab_bg_active_hover.gif)';
    }
}

function tab_change_off2() {
    if (document.getElementById('tab2') != null) {
        document.getElementById('tab2').style.backgroundImage = 'url(/images/tab_bg.gif)';
    }
}

function tab_change_on3() {
    if (document.getElementById('tab3') != null) {
        document.getElementById('tab3').style.backgroundImage = 'url(/images/tab_bg_active_hover.gif)';
    }
}

function tab_change_off3() {
    if (document.getElementById('tab3') != null) {
        document.getElementById('tab3').style.backgroundImage = 'url(/images/tab_bg.gif)';
    }
}