Check flle ext and size

by CJ Juarez

HTML

<form>
  <input type="file" name="file" id="confirm">
</form>

JavaScript

document.getElementById('confirm').addEventListener('change', checkFile, false);

function checkFile(e) {

    var file_list = e.target.files;

    for (var i = 0, file; file = file_list[i]; i++) {
        var sFileName = file.name;
        var sFileExtension = sFileName.split('.')[sFileName.split('.').length - 1].toLowerCase();
        var iFileSize = file.size;
        var iConvert = (file.size / 10485760).toFixed(2);

        if (!(sFileExtension === "jpg" || sFileExtension === "png" || sFileExtension === "bmp") || iFileSize > 10485760) {
            txt = "File type : " + sFileExtension + "\n\n";
            txt += "Size: " + iConvert + " MB \n\n";
            txt += "Please make sure your file is a valid image format and less than 10 MB.\n\n";
            alert(txt);
            document.getElementById("confirm").value = "";
        }
    }
}