Upload photo by php

//form to upload a file

<form action="" method="post" ENCTYPE="multipart/form-data">
<input type="file" name="photo"/>
<input type="submit" name="submit" value="Upload"/>
</form>


//PHP code

<?php
if(isset($_POST['submit'])) //if submit button is clicked
{
 if(isset($_FILES['photo'])) //if there is any file browsed
  {
         //check what is file extension
$s=strtolower($_FILES["photo"]["name"]); //get the file name

            $ext=end(explode('.', $s)); //explode the name from '.'; if the file name is abc.jpg, $ext will get value 'jpg'; this is to check file extension

         if($ext!='jpg' && $ext!='jpeg' && $ext!='png') //check the image type, you can add more type here
          {
              echo "Please choose jpg/jpeg/png file";
          }
         else if($_FILES["photo"]["size"]>1000000) //file maximum size 1mb
{
      echo "Please choose a file smaller than 1mb";
}
else{

$pat=$_SERVER['HTTP_HOST'].'/images/'.$_FILES["photo"]["name"];
     move_uploaded_file($_FILES["photo"]["tmp_name"],$pat); //upload the file

if($pat)echo "File uploaded";
}

  }
}

?>