Uncaught ReferenceError: removeLine is not defined

Question

I am using the following code from this SO answer, however it does work on here but when I try to remove an image on my side I get:

Uncaught ReferenceError: removeLine is not defined at HTMLSpanElement.onclick (https://example.com/test/createst/?myDates=2017&myCountry=Italia:1)

NOTE

One other bit I need to do is to create a preview of the uploaded images, I've found the following code by asking another question on SO where I actually had the opposite situation, managed to have a preview but not the remove

var dropZoneId = "drop-zone";
  var buttonId = "clickHere";
  var mouseOverClass = "mouse-over";
var dropZone = $("#" + dropZoneId);
 var inputFile = dropZone.find("input");
 var finalFiles = {};
$(function() {
  

  
  var ooleft = dropZone.offset().left;
  var ooright = dropZone.outerWidth() + ooleft;
  var ootop = dropZone.offset().top;
  var oobottom = dropZone.outerHeight() + ootop;
 
  document.getElementById(dropZoneId).addEventListener("dragover", function(e) {
    e.preventDefault();
    e.stopPropagation();
    dropZone.addClass(mouseOverClass);
    var x = e.pageX;
    var y = e.pageY;

    if (!(x < ooleft || x > ooright || y < ootop || y > oobottom)) {
      inputFile.offset({
        top: y - 15,
        left: x - 100
      });
    } else {
      inputFile.offset({
        top: -400,
        left: -400
      });
    }

  }, true);

  if (buttonId != "") {
    var clickZone = $("#" + buttonId);

    var oleft = clickZone.offset().left;
    var oright = clickZone.outerWidth() + oleft;
    var otop = clickZone.offset().top;
    var obottom = clickZone.outerHeight() + otop;

    $("#" + buttonId).mousemove(function(e) {
      var x = e.pageX;
      var y = e.pageY;
      if (!(x < oleft || x > oright || y < otop || y > obottom)) {
        inputFile.offset({
          top: y - 15,
          left: x - 160
        });
      } else {
        inputFile.offset({
          top: -400,
          left: -400
        });
      }
    });
  }

  document.getElementById(dropZoneId).addEventListener("drop", function(e) {
    $("#" + dropZoneId).removeClass(mouseOverClass);
  }, true);


  inputFile.on('change', function(e) {
    finalFiles = {};
    $('#filename').html("");
    var fileNum = this.files.length,
      initial = 0,
      counter = 0;

    $.each(this.files,function(idx,elm){
       finalFiles[idx]=elm;
    });

    for (initial; initial < fileNum; initial++) {
      counter = counter + 1;
      $('#filename').append('<div id="file_'+ initial +'"><span class="fa-stack fa-lg"><i class="fa fa-file fa-stack-1x "></i><strong class="fa-stack-1x" style="color:#FFF; font-size:12px; margin-top:2px;">' + counter + '</strong></span> ' + this.files[initial].name + '&nbsp;&nbsp;<span class="fa fa-times-circle fa-lg closeBtn" onclick="removeLine(this)" title="remove"></span></div>');
    }
  });



})

function removeLine(obj)
{
  inputFile.val('');
  var jqObj = $(obj);
  var container = jqObj.closest('div');
  var index = container.attr("id").split('_')[1];
  container.remove(); 

  delete finalFiles[index];
  //console.log(finalFiles);
}

#drop-zone {
  width: 100%;
  min-height: 150px;
  border: 3px dashed rgba(0, 0, 0, .3);
  border-radius: 5px;
  font-family: Arial;
  text-align: center;
  position: relative;
  font-size: 20px;
  color: #7E7E7E;
}
#drop-zone input {
  position: absolute;
  cursor: pointer;
  left: 0px;
  top: 0px;
  opacity: 0;
}
/*Important*/

#drop-zone.mouse-over {
  border: 3px dashed rgba(0, 0, 0, .3);
  color: #7E7E7E;
}
/*If you dont want the button*/

#clickHere {
  display: inline-block;
  cursor: pointer;
  color: white;
  font-size: 17px;
  width: 150px;
  border-radius: 4px;
  background-color: #4679BD;
  padding: 10px;
}
#clickHere:hover {
  background-color: #376199;
}
#filename {
  margin-top: 10px;
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.5em;
}
.file-preview {
  background: #ccc;
  border: 5px solid #fff;
  box-shadow: 0 0 4px rgba(0, 0, 0, 0.5);
  display: inline-block;
  width: 60px;
  height: 60px;
  text-align: center;
  font-size: 14px;
  margin-top: 5px;
}
.closeBtn:hover {
  color: red;
  display:inline-block;
}
}

<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.4.0/css/font-awesome.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<div id="drop-zone">
  <p>Drop files here...</p>
  <div id="clickHere">or click here.. <i class="fa fa-upload"></i>
    <input type="file" name="file" id="file" multiple />
  </div>
  <div id='filename'></div>
</div>