Question

I need jquery to check if my posted filename (up_image) is empty or not.

if it’s empty i need a div tag to be shown and come with some kind of alert message.

if not, just do the

$("#submit").submit();

    <form action="/profile/" method="post" enctype="multipart/form-data" id="submit">
    <p>
        <label for="up_image">image:</label>
        <input type="file" name="up_image" id="up_image" />     
    </p>
    <a href="javascript:;" id="post_submit" class="submit_btn">Upload</a>
</form>

Answer 1

$(function() {
  $("#post_submit").click(function() {
    var fil = $("#up_image");
    if($.trim(fil.val()).length == 0) {
      alert("Choose a file!");
      fil.focus();
      return false;
    }

    $("#submit").submit();
  });
});