upload file เฉพาะแค่ pdf doc docx แต่มันไม่เป็นไปตามเงื่อนไขที่กำหนด ช่วยทีครับ

<form name="from1" enctype="multipart/form-data" method="post" action="<?php $PHP_SELF;?>">
<table width="600" border="0" align="center">
  <tr>
    <td width="30%" >ICIE2015 - Send Paper</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td align="right">Paper Type</td>
    <td><select name="paper_type">
   		 	<option value="1">1</option>
     		<option value="2">2</option>
      		<option value="3">3</option>
       		<option value="4">4</option>
        	<option value="5">5</option>
        </select>
    </td>
  </tr>
  <tr>
    <td align="right">Publication Name*:</td>
    <td><input type="text" name="textlimit" id="textlimit" style="width:400px" maxlength="250"  value="<?php echo $_GET['data']; ?>"/></td>
  </tr>
    <tr>
    <td>&nbsp;</td>
    <td><div id="textlimitMAX" style="font-size:12px"></div></td>
  </tr>
  <tr>
    <td align="right">Abstract :</td>
    <td><textarea name="Wish" id="Wish" maxlength="700" style="width:400px"?><? echo $_GET['data2'];?> </textarea></td>
  </tr>
  <tr>
    <td height="24">&nbsp;</td>
    <td><div id="WishMax" style="font-size:12px"></div></td>
  </tr>
  <tr>
    <td align="right">*</td>
    <td><input name="upload" type="file"><font color="#FF0000" style="font-size:12px"> &nbsp; *File type .doc , .docx , .pdf</font></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td><input name="up" type="submit" value="Upload"></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
</table>
</form>
<?
$pid=select("tbl_paper","order by id desc limit 1");
$paper_id = "icie2015-".$pid[paper_type]."-".($pid[id]+1);
echo $paper_id;
$dir ="C:/AppServ/www/icie/paper";
//$upload_name = iconv('UTF-8','TIS-620',$upload_name);
$path="$dir/".$upload_name;
if($up)

{
	//$file = strtolower($_FILES["upload"]["name"]);
	//$type= strrchr($file,".");
	
	$data = $_POST["textlimit"];
	$data2 = $_POST["Wish"];
	$data3 = $_POST["paper_type"];
	echo $type;
	if($_POST["textlimit"] ==""){
		echo"<script language='JavaScript'>";
		echo"alert('Paper name not empty');"; 
		echo"location.href='http://localhost/icie/send_paper.php?data=$data';";
		echo"</script>";}
	else if(empty($upload_size)){
		echo"<script language='JavaScript'>";
		echo"alert('Please choose file upload.');";
		echo"window.location='http://localhost/icie/send_paper.php?data=$data&data2=$data2';";
		echo"</script>";}
	else if($_FILES['upload']['type'] != "application/pdf" || $_FILES['upload']['type'] != "application/msword" || $_FILES["upload"]["type"] == "application/vnd.openxmlformats-officedocument.wordprocessingml.document"){
		echo"<script language='JavaScript'>";
		echo"alert('File type not match.');";
		echo"window.location='http://localhost/icie/send_paper.php?data=$data&data2=$data2';";
		echo"</script>";
		echo $_FILES['upload']['type'];}
	else if(file_exists($path)){
		echo"<script language='JavaScript'>";
		echo"alert('File_exists.');";
		echo"window.location='http://localhost/icie/send_paper.php?data=$data&data2=$data2';";
		echo"</script>";}
	else if($_FILES['upload']['type'] == "application/pdf" || $_FILES['upload']['type'] == "application/msword" || $_FILES["upload"]["type"] == "application/vnd.openxmlformats-officedocument.wordprocessingml.document"){
		$sqlup = "Insert into tbl_paper(paper_id,user_id,paper_type,paper_name,paper_ab) values('$paper_id','$id',".$_POST["paper_type"]."','$upload_name','".$_POST["Wish"]."')" ;
		echo $sqlup;
		$objQuery = mysql_query($sqlup);
		if ($objQuery){
		copy($upload,$path);
		echo"<script language='JavaScript'>";
		echo"alert('OK.');";
		echo"window.location='http://localhost/icie/send_paper.php';";
		echo"</script>";
		mysql_close($conn);}
	}
}
?>
</body>
</html>