How do I get file size in megabytes using javascript?

Question

How do I create a function that will validate the size. See code below:

    var filename = $(this).get(0).files; //e.g. 2MB
    var maxFileSize = 10; //in megabytes (MB)
    IsFileSizeValid(file, maxFileSize); //returns true or false

    //Check file size is valid 
    function IsFileSizeValid(filename, maxFileSize) {
        /*TODO*/
    }

Answer 1

$(this).get(0).files[0].size - get first file size in bytes
$(this).get(0).files[0].size/1048576 - in MiB, 1048576 is 2^20 or 1024^2