<script>
	function checkplusupload() {
		var output = document.getElementById("output");
		var uploadform = document.forms.namedItem("uploadform");
		var csvfile = uploadform["csvfile"].value;
		alert(csvfile);

		if(csvfile == "" || csvfile == null) {
			alert("No filename specified! Please select a CSV file to process.");
		} else {
			output.innerHTML = "Please wait<blink>...</blink>";
			var data = new FormData(uploadform);
			var request = new XMLHttpRequest();
			request.open("POST", "uploadservlet", true);


			request.onreadystatechange = function() {
				  if (request.readyState == 4) {
					  output.innerHTML = "Uploaded!<br />";
					} else {
					  output.innerHTML = "Error " + request.status + " occurred uploading your file.<br />";
					}
			  };

			request.send(data);
		}
	}
</script>

<form method="POST" enctype="multipart/form-data" name="uploadform">
<label>CSV file:</label>
<input type="file" name="csvfile" required>
<input type="submit" value="Upload" onclick="checkplusupload()">
</form>