依赖表单字段问题

Need to know what the name of form field? created when user clicks on checks checkbox?

<html>
<head>
<title>Sample from PHP Server File Uploader Script</title>

<!––Script for Checkbox new Filename field––>
    <script type="text/javascript">
 function dynInput(cbox) {
  if (cbox.checked) {
    var input = document.createElement("input");
    input.type = "text";
    var div = document.createElement("div");
    div.id = cbox.name;
    div.innerHTML = "Enter New File Name here";
    div.appendChild(input);
    document.getElementById("insertinputs").appendChild(div);
  } else {
    document.getElementById(cbox.name).remove();
  }
}
</script>    
<!--End of Script for Checkbox new Filename field-->

</head>
<form method="post">
<strong>Enter Direct File URL:<br></strong>
<input name="url" size="50" /><br><br>
<strong>File name:<br></strong>
<input type="checkbox" name="Leech" onclick="dynInput(this);"> Use Different Filename?
<!--Position for New filename field-->
<p name= "filename" id="insertinputs"></p>
<input name="submit" type="submit" />
</form>

I am newbie to coding! Where am attempting to create Remote URL PHP File uploader for server!

I am almost done now I am adding more code so that user can customise file name as well! Any help would be grateful!

View working code at PHP Server File uploader

i think you are looking for this : put this code below of this line :

 var input = document.createElement("input");
 input.setAttribute('name',   'new_attribute');