function ValidPrice(obj)
{ s = obj.value;
//var reg = /^[0-9]*\.[0-9]{0,2}$/;
var reg = /^[0-9]+([.]{1}[0-9]{1,2})?$/;
if (!reg.test(s))
{
obj.value = "";
alert("必须为>=0的金额，精确到小数点后2位!");
obj.focus();
obj.select();
return false;
}
return true;
}
原文：http://www.cnblogs.com/neights/p/4493155.html