angularJS 脏值检查

<input ng-model="addr_y" id="addr_y" type="text" ng-change="textChange(addr_y)" />

$scope.doUpdate = function(){
var change = instance.change;
 
if(!$scope.shopname){
alert("药店名称不能为空,请输入...");
return;
}
................................
if(!$scope.addr_y){
alert("银行纬度不能为空,请输入...");
return;
}
$scope.textChange = function(val){
//        alert('变化了');
        instance.change = true;
    }
//alert(change);
if(!change){
alert("药店信息未做任何更改");
}else{
appCallServer($http,"G016",{"mangid":localStorage.mangid,
"shopid":"S"+$scope.phone,
 ...............
"addr_x":$scope.addr_x,
"addr_y":$scope.addr_y
},
function(data){
//success function
alert("保存药店信息成功");
instance.change = false;
//window.location="index.html";
});
}
};