How to convert the amount from lowercase to uppercase in js

    function DX(n) {
        if(!/^(0|[1-9]\d*)(\.\d+)?$/.test(n))              
        return "";
        var unit = "仟佰拾亿仟佰拾万仟佰拾元角分",
            str = "";
        n += "00";
        var p = n.indexOf('.');
        if(p >= 0)
            n = n.substring(0, p) + n.substr(p + 1, 2);
        unit = unit.substr(unit.length - n.length);
        for(var i = 0; i < n.length; i++)
        return str.replace(/零(仟|佰|拾|角)/g, "零").replace(/(零)+/g, "零").replace(/零(万|亿|元)/g, "$1").replace(/(亿)万|壹(拾)/g, "$1$2").replace(/^元零?|零分/g, "").replace(/元$/g, "元整");

    }