asp.net+js实现金额格式化

<asp:TextBox ID="txtAmount" runat="server" onkeypress="check()" onkeyup="run(this)"></asp:TextBox>

//======检查输入的是否为数字
function check() {
    if (!((window.event.keyCode >= 48 && window.event.keyCode <= 57) || window.event.keyCode == 46 || window.event.keyCode == 45)) {
        window.event.keyCode = 0
    }
}
//======格式化文本框的金额
function run(obj) {
    var objvalue = obj.value.replace(/[,]/g, ""),
        objlength = objvalue.length,
        dtmp = objvalue.indexOf("."),
        neg = objvalue.indexOf("-");
    var inttmp = 0,
        floattmp = -1;
    if (dtmp != -1) {
        inttmp = dtmp == 0 ? "0" : new String(objvalue).substring(0, dtmp);
        floattmp = new String(objvalue).substring(dtmp + 1, objlength + 1);
        floattmp = floattmp.replace(/[^0-9]/g, "");
    }
    else {
        inttmp = objvalue;
    }
    if (neg == 0) {
        inttmp = inttmp.replace(/[-]/g, "");
    }
    inttmp = inttmp.replace(/[^0-9]/g, "");
    var tmp = "", str = "0000";
    for (; inttmp.length > 3; ) {
        var temp = new String(inttmp / 1000);
        if (temp.indexOf(".") == -1) {
            tmp = ",000" + tmp;
            inttmp = temp;
        }
        else {
            var le = new String(temp).split(".")[1].length;
            tmp = "," + new String(temp).split(".")[1] + str.substring(0, 3 - le) + tmp;
            inttmp = new String(temp).split(".")[0];
        }
    }
    inttmp = inttmp + tmp;
    obj.value = neg == 0 ? "-" + inttmp + runing(floattmp) : inttmp + runing(floattmp);
}
//======整理小数部分
function runing(val) {
    if (val != "-1" && val != "") {
        var valvalue = 0 + "." + val;
        if (val.length >= 2) {
            valvalue = parseFloat(valvalue).toFixed(2);
        }
        var temp = "." + valvalue.split(".")[1];
        return temp;
    }
    else if (val != "0" && val == "") {
        return ".";
    }
    else {
        return "";
    }
}