String.prototype.trim = function() {
    //   用正则表达式将前后空格用空字符串替代。
    var t = this.replace(/(^\s*)|(\s*$)/g, "");
    return t.replace(/(^　*)|(　*$)/g, "");
}

function doZoom(size, lineheight) {
    document.getElementById('zoom').style.fontSize = size + 'px'
    document.getElementById('zoom').style.lineHeight = lineheight + 'px'
}

function chg_menu(str, strers) {
    var tary = strers.split(",");
    
    for (i = 0; i < tary.length; i++) {
        if (tary[i] == str) {
            document.getElementById(tary[i]).src = "img/" + tary[i] + "_b.jpg";
            document.getElementById("area_" + tary[i]).style.display = '';

        }
        else {
            document.getElementById(tary[i]).src = "img/" + tary[i] + ".jpg";
            document.getElementById("area_" + tary[i]).style.display = 'none';
        }
    }
}