var ver4 = (navigator.appVersion.charAt(0) >= "4");
var NN4  = ver4 && (navigator.appName.charAt(0) == "N");
var IE4  = ver4 && (navigator.appName.charAt(0) == "M");
var NN3  = ((navigator.appVersion.charAt(0) == "3") &&
            (navigator.appName.charAt(0) == "N"));

if(NN3 || NN4 || IE4){
var img_b = new Array();
img_b[1] = new Image(); img_b[1].src = "images/koumoku01a.gif"
img_b[2] = new Image(); img_b[2].src = "images/koumoku02a.gif"
img_b[3] = new Image(); img_b[3].src = "images/koumoku03a.gif"
img_b[4] = new Image(); img_b[4].src = "images/koumoku04a.gif"
img_b[5] = new Image(); img_b[5].src = "images/koumoku05a.gif"
img_b[6] = new Image(); img_b[6].src = "images/koumoku06a.gif"
img_b[7] = new Image(); img_b[7].src = "images/koumoku07a.gif"
img_b[8] = new Image(); img_b[8].src = "images/koumoku08a.gif"
img_b[9] = new Image(); img_b[9].src = "images/koumoku09a.gif"
img_b[10] = new Image(); img_b[10].src = "images/koumoku10a.gif"
img_b[11] = new Image(); img_b[11].src = "images/koumoku01b.gif"
img_b[12] = new Image(); img_b[12].src = "images/koumoku02b.gif"
img_b[13] = new Image(); img_b[13].src = "images/koumoku03b.gif"
img_b[14] = new Image(); img_b[14].src = "images/koumoku04b.gif"
img_b[15] = new Image(); img_b[15].src = "images/koumoku05b.gif"
img_b[16] = new Image(); img_b[16].src = "images/koumoku06b.gif"
img_b[17] = new Image(); img_b[17].src = "images/koumoku07b.gif"
img_b[18] = new Image(); img_b[18].src = "images/koumoku08b.gif"
img_b[19] = new Image(); img_b[19].src = "images/koumoku09b.gif"
img_b[20] = new Image(); img_b[20].src = "images/koumoku10b.gif"
}

function B_in(nam,num){
if(NN3 || NN4 || IE4) document.images[nam].src = img_b[num].src;
}

function B_out(nam,num){
if(NN3 || NN4 || IE4) document.images[nam].src = img_b[num].src;
return false;
}