PHP - Check Image Type

hi guys,  in my form i need to insert an ID which is 5 digits number only. can anyone please tell me how can i check this before i insert? and also i need to check existing ID in my database.

Is there a diffrent image type refference in php for the file extentions 'jpg' & 'jpeg'. For example i have allowed "image/jpeg" files to be uploaded but only files with the extention .jpg are going through were as .jpeg are not, any idea's?

Hey guys I have this script that edits a users profile, but the problem is that it doesnt want to upload it to the server and keeps saying.

Files must be either JPEG, GIF, or PNG and less than 10,000 kb



 
<?php
if(empty($_GET['id']) ) { 
echo 'Category not specified'; 
} else {




 mysql_connect("localhost","root","") or die(mysql_error());
 mysql_select_db("chat");
 $result = mysql_query("SELECT * FROM users WHERE user_id = '$_GET[id]'");
 $query = mysql_fetch_array($result);
 
 
 if (isset($_POST['submit'])) { 

$target = "mainnewsimg/"; 
 $target = $target . basename( $_FILES['photo']['name']); 
  
      // Set global variables to easier names

  $pic=($_FILES['photo']['name']); 

  

  

  

 if (($_FILES["photo"]["type"] == "image/gif")
  || ($_FILES["photo"]["type"] == "image/jpeg")
  || ($_FILES["photo"]["type"] == "image/png" )
  && ($_FILES["photo"]["size"] < 10000))
  { 

   if(move_uploaded_file($_FILES['photo']['tmp_name'], $target)) 
 { 

    mysql_query("UPDATE users SET 

level ='". $_POST['rank'] ."',

email='". $_POST['email'] ."',

fname='". $_POST['fname'] ."',

lname='". $_POST['lname'] ."',

avatar='$pic'

WHERE user_id='". $_GET['id'] ."' "); 

echo "user updated";

  }

  else
  {
  echo "file hasent been moved to uploads";
  }

  }

  else
  {
  echo "Files must be either JPEG, GIF, or PNG and less than 10,000 kb";
  }
 


 //mysql_query("UPDATE Persons SET level = '36'WHERE user_id = '$_GET[id]'");


}
 

?>

<?php echo $query['username']; ?>
<form method="post" action="">
<table>

<tbody>

<tr><td class="first"></td>

<td><?php echo $query['user_id']; ?></td></tr>

<tr><td class="first">First Name</td>

<td><input type="text" name="fname" value="<?php echo $query['fname']; ?>" ></td></tr>

<tr><td class="first">Last Name</td>

<td><input type="text" name="lname" value="<?php echo $query['lname']; ?>" ></td></tr>

<tr><td class="first">Email</td>

<td><input type="text" name="email" value="<?php echo $query['email']; ?>" ></td></tr>

<tr><td class="first">Rank</td>

<td><select name="rank">
<option value="0" <?php if($query['level']=="0") { echo "selected"; }?>>Unactivated</option> 
<option value="1" <?php if($query['level']=="1") { echo "selected"; }?>>Banned</option> 
<option value="2" <?php if($query['level']=="2") { echo "selected"; }?>>Regular User</option> 
<option value="3" <?php if($query['level']=="3") { echo "selected"; }?>>Donator</option> 
<option value="4" <?php if($query['level']=="4") { echo "selected"; }?>>Moderator</option> 
<option value="5" <?php if($query['level']=="5") { echo "selected"; }?>>Administrator</option> 
<option value="6" <?php if($query['level']=="6") { echo "selected"; }?>>Owner</option> 
</select>

</td></tr>

<tr><td class="first">User 

Avatar</td>

<td><input type="file" name="photo"></td></tr>

<tr><td class="first">Joined on</td>

<td><input type="text" name="join" value="<?php echo date('d-F-Y',($query['join_date'])); ?>" disabled="disabled"></td></tr>

<tr><td class="first">Last Access</td>

<td><input type="text" name="access" value="" disabled="disabled"></td></tr>

<tr><td></td>

<td>

<input type="submit" name="submit" value="Edit User">

</td></tr>

</tbody></table>


</form>




<?php } ?>

hi evry bdy i m new to php
here is my big problem
im trying to display images and resize but header tag in php not working here is my code




<?php

   header('Content-type: image/jpeg');
   $new_width = 200;
   $new_height = 200;
   $files = glob("images/*.*");
   //print_r($files);
   //for ($i=0; $i<count($files); $i++) {
      $filename= $files[0];
      print $filename."<br />";
      list($width, $height) = getimagesize($filename);
      echo "width is".$width." and height is ".$height;
      echo '<img src="'.$filename.'" alt="random image" />'."<br /><br />";
      $image_p = imagecreatetruecolor($new_width, $new_height);
      $image = imagecreatefromjpeg($filename);
      imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
      imagejpeg($image_p, null, 100);

      
   //}

?>
if i m commenting header in line 3 then it is displaying garbage value
if i m not commenting then it is displaying filename as string ... i wanna resize image
please help me.....