SQL Injection Filter

<?php
function SQLInjectionTest($checkstring)
{
$sqltest = array ("/SELECT.*/i",
"/INSERT.*/i",
"/DELETE.*/i",
"/UPDATE.*/i",
"/ALTER.*/i",
"/DROP.*/i",
"/CREATE.*/i",
"/substr/i",
"/varchar/i",
"/or.*\d=\d/i",
"/and.*\d=\d/i");
foreach ($sqltest as $regex)
{
if (preg_match($regex, $checkstring))
{
return TRUE;
}
}
return FALSE;
}


function check_inej()
{
 foreach ($_POST as $key => $value)
  {

    if ( SQLInjectionTest($value))
  {
  echo "<h1> SQL INJECTION DETECTED!!! </h1>";
  exit(0);
  }
   }


   foreach ($_GET as $key => $value)
  {

    if ( SQLInjectionTest($value))
  {
  echo "<h1> SQL INJECTION DETECTED!!! </h1>";
  exit(0);
  }
   }
}

check_inej();


?>