if (document.images) {
        var button1off = new Image()
        button1off.src = "/images/nav/nav_off_01.gif"
        var button1on = new Image()
        button1on.src = "/images/nav/nav_over_01.gif"
        
        var button2off = new Image()
        button2off.src = "/images/nav/nav_off_02.gif"
        var button2on = new Image()
        button2on.src = "/images/nav/nav_over_02.gif"
        
        var button3off = new Image()
        button3off.src = "/images/nav/nav_off_03.gif"
        var button3on = new Image()
        button3on.src = "/images/nav/nav_over_03.gif"

        var button4off = new Image()
        button4off.src = "/images/nav/nav_off_04.gif"
        var button4on = new Image()
        button4on.src = "/images/nav/nav_over_04.gif"

        var button5off = new Image()
        button5off.src = "/images/nav/nav_off_05.gif"
        var button5on = new Image()
        button5on.src = "/images/nav/nav_over_05.gif"

        var button6off = new Image()
        button6off.src = "/images/nav/nav_off_06.gif"
        var button6on = new Image()
        button6on.src = "/images/nav/nav_over_06.gif"
        
        var button7off = new Image()
        button7off.src = "/images/nav/nav_off_07.gif"
        var button7on = new Image()
        button7on.src = "/images/nav/nav_over_07.gif"

        var button8off = new Image()
        button8off.src = "/images/nav/nav_off_08.gif"
        var button8on = new Image()
        button8on.src = "/images/nav/nav_over_08.gif"

        var button9off = new Image()
        button9off.src = "/images/nav/nav_off_09.gif"
        var button9on = new Image()
        button9on.src = "/images/nav/nav_over_09.gif"
}

function act(imgName) {
        if (document.images) {
                document[imgName].src = eval(imgName + 'on.src')
        };
}

function inact(imgName) {
        if (document.images) {
                document[imgName].src = eval(imgName + 'off.src')
        };
}