How to concatenate and upload multiple file in php

I need to do concatenate and upload multiple files using PHP. But, this is not working properly. can anyone help me please.

if(mkdir($StudentPicturesPath.UserSyear().'./Docs/'.UserStudentID(),0777));        
        $target_path=$StudentPicturesPath.UserSyear().'./Docs/'.UserStudentID().'/'.UserStudentID().'_BirthCertificate.PDF';
        $target_path1 = file_get_contents($target_path);
            $target_path1=$StudentPicturesPath.UserSyear().'./Docs/'.UserStudentID().'/'.UserStudentID().'_NIC.PDF';

            file_get_contents($target_path,$target_path1);


            $destination_path = $StudentPicturesPath.UserSyear();       #$target_path=$StudentPicturesPath.UserSyear().'/'.UserStudentID().'.JPG';
        $upload= new upload();
        $upload->target_path=$target_path;
            $upload->target_path1=$target_path1;

        $upload->destination_path=$destination_path;
        $upload->name=$_FILES["file"]["name"];
        $upload->setFileExtension();
        $upload->fileExtension;

This is the my another code. These are in the same file. I upload the file using form submission. There are 2 <input>.

    move_uploaded_file($_FILES["file"]["tmp_name"], $upload->target_path);
      @fopen($upload->target_path,'r');
      //echo '<div align=center><IMG SRC="'.$upload->target_path.'?id='.rand(6,1000000).'"  width=150 class=pic></div><div class=break></div>';
      echo '<div align=center><a href="'.$upload->target_path.'?id='.rand(6,1000000).'" width=150 class=pic></div><div class=break></div>';

          fclose($upload->target_path);
      echo "<b>Copied file to " .$upload->destination_path."</b><p>";
      $filename =  $upload->target_path;
      PopTable ('footer');


          move_uploaded_file($_FILES["file"]["tmp_name"], $upload->target_path1);
      @fopen($upload->target_path1,'r');
      //echo '<div align=center><IMG SRC="'.$upload->target_path.'?id='.rand(6,1000000).'"  width=150 class=pic></div><div class=break></div>';
      echo '<div align=center><a href="'.$upload->target_path1.'?id='.rand(6,1000000).'" width=150 class=pic></div><div class=break></div>';

          fclose($upload->target_path1);
      echo "<b>Copied file to " .$upload->destination_path."</b><p>";
      $filename =  $upload->target_path1;
      PopTable ('footer');
    }    
}


else
{
echo '
'.$msg.'
<form enctype="multipart/form-data" action="Modules.php?modname=Students/UploadFile.php&action=upload" method="POST">';
echo '<div align=center>Select Birth Certificate File: <input name="file" type="file" /><br /><br>';
echo '<div align=center>Select NIC File: <input name="file1" type="file" /><br /><br>';

echo '<input type="submit" value="Upload" class=btn_medium />&nbsp;<input type=button class=btn_medium value=Cancel onclick=\'load_link("Modules.php?modname=Students/Student.php");\'></div>
</form>';
PopTable ('footer');
}