input只能输入数字和小数点，并且只能保留小数点后两位

1.给文本框添加一个onkeyup=’clearNoNum(this)’点击事件
2.建立clearNoNum方法

function clearNoNum(obj) { 
    obj.value = obj.value.replace(/[^\d.]/g,""); //清除"数字"和"."以外的字符 
        obj.value = obj.value.replace(/^\./g,""); //验证第一个字符是数字而不是 
        obj.value = obj.value.replace(/\.{2,}/g,"."); //只保留第一个. 清除多余的 
        obj.value = obj.value.replace(".","$#$").replace(/\./g,"").replace("$#$",".");  
        obj.value = obj.value.replace(/^(\-)*(\d+)\.(\d\d).*$/,'$1$2.$3'); //只能输入两个小数 

}  

3将金额小写转换成大写

function onlyNumber1(input, n) { 
    var ret = "";  
    var number =input.value;  
if (number != ""&& number!=null&&number!="0") {  
                var unit = "仟佰拾亿仟佰拾万仟佰拾元角分",  
                str = "";  
number += "00";  
                var point = number.indexOf('.');  
if (point >= 0) {  
number = number.substring(0, point) + number.substr(point + 1, 2);  
                }  
                unit = unit.substr(unit.length - number.length);  
for (var i = 0; i < number.length; i++) {  
                    str += '零壹贰叁肆伍陆柒捌玖'.charAt(number.charAt(i)) + unit.charAt(i);  
                }  
                ret = str.replace(/零(仟|佰|拾|角)/g, "零").replace(/(零)+/g, "零").replace(/零(万|亿|元)/g, "$1").replace(/(亿)万|(拾)/g, "$1$2").replace(/^元零?|零分/g, "").replace(/元$/g, "元") + "整";  
        }  
    var a = document.getElementsByName("MoneyCapital")[0].id;  
    document.getElementById(a).value=ret;     
    }