Funcion para subir una imagen

uploadImg.php

<?php 
 function upload_image($destination_dir, $name_media_field, $intfecha){
        $tmp_name = $_FILES[$name_media_field]['tmp_name'];
        if (is_dir($destination_dir) && is_uploaded_file($tmp_name)) {
            $img_file = strtolower(str_replace(" ", "", $_FILES[$name_media_field]['name']));
            $img_type = $_FILES[$name_media_field]['type'];

            if (((strpos($img_type, "gif") || strpos($img_type, "jpeg") || strpos($img_type, "jpg")) || strpos($img_type, "png"))) {
                if (move_uploaded_file($tmp_name, $destination_dir . '/' . $intfecha . $img_file))  return true;
            }
        }
        return false;
  }

?>