按比例调整背景图像大小(Resizing background image proportionally)

 似乎它不是关于运行一个函数， 如果另一个函数是成功的 ，但是在异步操作完成之后 。 在calcRoute ，路由计算API调用是异步的; 这意味着函数将在 directionsService完成创建路径之前返回。 一种解决方案是修改calcRoute以进行回调： 
 
function calcRoute(callback) {
    var start = document.getElementById('start').value;
    var end = "Via Tiburtina 500, Roma";
    var request = {
        origin:start,
        destination:end,
        travelMode: google.maps.DirectionsTravelMode.TRANSIT
    };
    directionsService.route(request, function(response, status) {
      if (status == google.maps.DirectionsStatus.OK) {
        directionsDisplay.setDirections(response);

        // If a callback was passed, run it
        if(typeof callback === "function") {
            callback();
        }

      }
    });
}
 
 然后更改函数调用以传递回调： 
 
<form onsubmit="calcRoute(function(){ boxappear(); reducemap(); }); return false">
 
 旁注：我不建议在HTML属性中内联代码，混合结构和行为，也可能变得难以维护; 我建议调查将事件附加到DOM元素的其他方法。 

It seems it's not about running one function if the other one is succesful, but after an asynchronous operation is done. In calcRoute, the route calculation API call is asynchronous; that means the function will return before the directionsService finishes creating the route. One solution is to modify calcRoute to take a callback:
 
function calcRoute(callback) {
    var start = document.getElementById('start').value;
    var end = "Via Tiburtina 500, Roma";
    var request = {
        origin:start,
        destination:end,
        travelMode: google.maps.DirectionsTravelMode.TRANSIT
    };
    directionsService.route(request, function(response, status) {
      if (status == google.maps.DirectionsStatus.OK) {
        directionsDisplay.setDirections(response);

        // If a callback was passed, run it
        if(typeof callback === "function") {
            callback();
        }

      }
    });
}
 
Then change your function call to pass the callback:
 
<form onsubmit="calcRoute(function(){ boxappear(); reducemap(); }); return false">
 
Side note: I wouldn't recommend inlining code in HTML attributes like that, is mixes structure and behavior, and can also become hard to maintain; I suggest looking into other ways of attaching events to DOM elements.