class DocumentUpload
{
	//Variables values gained from the __construct() method
	public $inputName;
	public $original;
	public $timeOriginal;
	public $tempName;
	public $docType;
	public $folder;
	public $dbFolder;
	public $page;
	public $pathAndFile;
	public $pathTimeFile;
	public $dbFile;
	public $dbTimeFile;
	//Variables used in the upload() method
	public $thumb;
	public $success;
	public $result;
	public $mailSubject = "";
	//Variable used to see which path and filename must be added to the database
	public $timedFile;
 
	//Array of acceptable MIME types
	public $permitted = array('application/pdf', 'application/zip', 'application/msword', 'application/vnd.ms-powerpoint', 'application/vnd.ms-excel');
    //variables set assuming the file is unacceptable
	public $sizeOK = false;
	public $typeOK = false;
 
	public function __construct($inputName, $folder, $dbFolder, $page)
	{
		$this->inputName			= $inputName;
		$this->original				= str_replace(array(" ", 'PDF'), array("_", 'pdf'), $_FILES[''.$inputName.'']['name']);
		$this->timeOriginal			= time().$this->original;
		$this->tempName				= $_FILES[''.$inputName.'']['tmp_name'];
		$this->docType				= $_FILES[''.$inputName.'']['type'];
		$this->folder				= $folder;
		$this->dbFolder				= $dbFolder;
		$this->pathAndFile			= $folder.$this->original;
		$this->pathTimeFile			= $folder.time().$this->original;
		$this->dbFile				= $dbFolder.$this->original;
		$this->dbTimeFile			= $dbFolder.time().$this->original;
		$this->page					= $page;
	}
 
 
	//Upload an image to the server
	public function upload($chmod)
	{
		//check that the file is of a permitted MIME type
		foreach($this->permitted as $type)
		{
			if($type == $this->docType)
			{
				$this->typeOK = true;
				break;
			}
		}
 
		//Check if the file type has been verified as valid
		if($this->typeOK)
		{
			switch($_FILES[''.$this->inputName.'']['error'])
			{
				case 0:
					// Make sure file of the same name does not exist
					if (!file_exists($this->pathAndFile))
					{
						$this->success = move_uploaded_file($this->tempName, $this->pathAndFile);
						chmod($this->pathAndFile, $chmod);
 
						//Variable used to see which path and filename must be added to the database
						$this->timedFile = false;
					}
					else
					{
						$this->success = move_uploaded_file($this->tempName, $this->pathTimeFile);
						chmod($this->pathTimeFile, $chmod);
 
						//Variable used to see which path and filename must be added to the database
						$this->timedFile = true;
					}
 
					//If the file was uploaded
					if ($this->success)
					{
						$this->result = "Document added successfully.";
					}
					else
					{
						$this->result = "There was an error uploading the file. <a class=\"clrBrown\" href='".$this->page."' >Please try again</a>.";
					}
					break;
				case 3:
					$this->result = "There was an error uploading the file. <a class=\"clrBrown\" href='".$this->page."' >Please try again</a>.";
				default:
					$this->result = "System error uploading file. Contact the <a class=\"clrBrown\" href=\"mailto:test@website.com".$this->mailSubject."\">webmaster</a>";
			}
		}
		else if($_FILES[''.$this->inputName.'']['error'] == 4)
		{
			$this->result = 'No file selected';
		}
		else
		{
			$this->result = "File cannot be uploaded. Acceptable file types: ppt, xls, doc, pdf, zip. <a class=\"clrBrown\" href='".$this->page."' >Please try again</a>.";
		}
	}
}

<?php
function validate_pdf($path) {
	$fh = fopen($path, "rb");
	if($fh) {
		$header = fread($fh, 4);
		if($header == "%PDF") {
			return true;
		}
		else {
			return false;
		}
	}
	else {
		return false;
	}
}
?>