var cando = false;
var browserName = navigator.appName;
var browserVer = parseInt(navigator.appVersion);
if (browserName == "Netscape" && browserVer >= 3) cando = true;
else if( browserVer >=4 ) cando=true;
if( cando ) {
        imag = new Array();
        imag[0] = "img/but/but_off_1.gif";
        imag[1] = "img/but/but_on_1.gif";
        imag[2] = "img/but/but_off_2.gif";
        imag[3] = "img/but/but_on_2.gif";
        imag[4] = "img/but/but_off_3.gif";
        imag[5] = "img/but/but_on_3.gif";
        imag[6] = "img/but/but_off_4.gif";
        imag[7] = "img/but/but_on_4.gif";
        imag[8] = "img/but/but_off_5.gif";
        imag[9] = "img/but/but_on_5.gif";
        imag[10] = "img/but/but_off_6.gif";
        imag[11] = "img/but/but_on_6.gif";
        imag[12] = "img/but/but_off_7.gif";
        imag[13] = "img/but/but_on_7.gif";
        imag[14] = "img/but/but_off_8.gif";
        imag[15] = "img/but/but_on_8.gif";

im = new Array()
        for (var i = 0; i < imag.length; i++){
                if( imag[i] != "" ) {
                        im[i] = new Image();
                        im[i].src = imag[i];
                }
        }
}

function swtch(num,imgname){
        if( cando )
        document[imgname].src = im[num].src;
}