JAVASCRIPT

I am folllowing this tutorial "Using Google maps Javascript api in HTML (Show location with Marker)" but as this example shows how to add only one location with marker in google maps. I would like to add multiple markers in multiple locations of maps. How can I do it. Suppose I have following locations in an array:

Hello, I have a HTML form inside which there is <input type="file" /> field, and now before posting form to the server side, I need to validate/check if file field is empty or not, I want user to upload atleast one image file in this field, so how I can implement validation message for <input type ="file" /> field in the form using jQuery or javascript code?

Sample HTML Form

Is there any way to make Ajax request Synchronous in jQuery/javascript?

I am trying to fetch a data from the server while loading the <div> data and depending on that data, i will fetch another query, which can be asynchronous but the first one should be synchronous as data will be parsed after the success of the call.

Code:

Hello, I am working on a web-application in which I would to upload file using javascript, as soon as someone select's the file using HTML file input, so what should be the code for uploading file using javascript?

Although I need only front-end code/tutorial link etc, but if possible i would like to know C# code to get it in MVC Controller also, thanks.