JS 实现数据分割1，123，456

        <asp:TextBox ID="txt2" runat="server" CssClass="decimalInput_R" onkeydown="decimalInput(this, 8, 5)" onkeyup="decimalFormat(this)"></asp:TextBox>

/*
==================================================================
decimal类型数据的输入检查

element:input text
dotLeft:整数部分位数
dotRight:小数部分位数
==================================================================
*/
function decimalInput(element, dotLeft, dotRight) {
    if( (event.keyCode == 13 || event.keyCode == 8 || (event.keyCode == 110 && !hasChar(element.value, ".")))
         || (((event.keyCode >= 48 && event.keyCode <= 57) || (event.keyCode >= 96 && event.keyCode <= 105))
                && decimalLength(element.value, dotLeft, dotRight) )) {
        event.returnValue = true;
    } else {
        event.returnValue = false;
    }
}

/*
==================================================================
Decimal数据类型数据的格式化
==================================================================
*/
function decimalFormat(element) {
    if ((event.keyCode >= 48 && event.keyCode <= 57)
        || (event.keyCode >= 96 && event.keyCode <= 105)
        || event.keyCode == 13|| event.keyCode == 8
        || event.keyCode == 110) {
        var value = element.value;
        if(value != "") {
            var arr = value.split(".");
            if(arr.length == 1) {
                var arrInt = arr[0].split("");
                var newValue = arrInt[arrInt.length-1];
                var count = 0;
                for(i = arrInt.length - 2; i >= 0 ; i--) {
                    if(arrInt[i] === ",") {
                        continue;
                    }
                    count++;
                    if(count === 3) {
                        newValue = "," + newValue;
                        count = 0;
                    }
                    newValue = arrInt[i] + newValue;
                }
                if(typeof(newValue) != "undefined") {
                    element.value = newValue;
                }
                return;
            }
        }
    }
}