Subir imagen por ajax automaticamente

<img onclick="jQuery('#file').click()" id="imageUpload" src="uploads/images/flyer_picture/{{$fly->detail}}" style="width:200px;height:200px;"/>
<input type="file" id="file" name="pic" style="display: none;"/>

<script>
//-------------------------------------------
  //Subir imagen
  $("#file").change(function(){
    readURL(this);
    var inputFileImage = document.getElementById("file");
    var file = inputFileImage.files[0];
    var data = new FormData();
    data.append('file',file);
    $.ajax({
      url:"/flyerPicture",
      type:'POST',
      contentType:false,
      data:data,
      processData:false,
      cache:false}).done(function(data){
          if(file!=undefined){
        $("#timelinePost").prepend("<img src='"+file.name+"' >");
          }
      });

  });

  function readURL(input) {
    if (input.files && input.files[0]) {
      var reader = new FileReader();
      reader.onload = function (e) {
        $('#imageUpload').attr('src', e.target.result);
      }
      reader.readAsDataURL(input.files[0]);
    }
  }
//END Subir imagen
//------------------------------------------
</script>