function headerOver(id){
    document.getElementById(id).src="http://maruhabi.mast-ichii.jp/images/"+id+"_on.jpg";
}
function headerOut(id){
    document.getElementById(id).src="http://maruhabi.mast-ichii.jp/images/"+id+"_off.jpg";
}


var speed = 5;
var nowAlpha = 100;
var swc = 0;
var swc_flg = true;
var set_flg = true;


function mainImgChange(){
    if(swc == 10){
        swc = 0;
    }else if(swc % 2 == 0){
        if(swc_flg){
            if(nowAlpha <= 0){
                swc_flg = false;
                document.getElementById("main_left").src = "http://maruhabi.mast-ichii.jp/images/main_" + swc + ".jpg";
            }else{
                nowAlpha -= speed;
                document.getElementById("main_left").style.filter = "alpha(opacity=" + nowAlpha + ")";
                document.getElementById("main_left").style.MozOpacity  = nowAlpha / 100;
                document.getElementById("main_left").style.opacity  = nowAlpha / 100;
            }
        }else{
            if(nowAlpha >= 100){
                swc_flg = true;
                swc++;
            }else{
                nowAlpha += speed;
                document.getElementById("main_left").style.filter = "alpha(opacity=" + nowAlpha + ")";
                document.getElementById("main_left").style.MozOpacity  = nowAlpha / 100;
                document.getElementById("main_left").style.opacity  = nowAlpha / 100;
            }
        }
    }else{
        if(swc_flg){
            if(nowAlpha <= 0){
                swc_flg = false;
                document.getElementById("main_right").src = "http://maruhabi.mast-ichii.jp/images/main_" + swc + ".jpg";
            }else{
                nowAlpha -= speed;
                document.getElementById("main_right").style.filter = "alpha(opacity=" + nowAlpha + ")";
                document.getElementById("main_right").style.MozOpacity  = nowAlpha / 100;
                document.getElementById("main_right").style.opacity  = nowAlpha / 100;
            }
        }else{
            if(nowAlpha >= 100){
                swc_flg = true;
                swc++;
                set_flg = false;
            }else{
                nowAlpha += speed;
                document.getElementById("main_right").style.filter = "alpha(opacity=" + nowAlpha + ")";
                document.getElementById("main_right").style.MozOpacity  = nowAlpha / 100;
                document.getElementById("main_right").style.opacity  = nowAlpha / 100;
            }
        }
    }
    if(set_flg){
        setTimeout("mainImgChange()",50);
    }else{
        setTimeout("mainImgChange()",5000);
        set_flg = true;
    }
}