在低版本的ie浏览器中当onpropertychange事件中有alert时会一直alert，

解决办法：判断上次输入的值是否和本次输入一样，输入一样则不执行alert

var tempAmounts = '';

function calculateAmount(obj){
var id = $(obj).attr("id");
var settlementAmount = $(obj).val();

if (tempAmounts== settlementAmount){
return;
}
tempAmounts= settlementAmount;

alert(111);

......

}