<form id="form1" name="form1" method="post" action="a.php?Git=Sonuc">
Rakam Girin :  <input type="text" name="rakam" id="deger" />
<input type="submit" name="Submit" id="Submit" value="Gonder" />
</form>
<?php

function Donustur($cevir) {
	
$sayi = array("0","1","2","3","4","5","6","7","8","9");	
$harf = array("sifir ","bir ","iki ","uc ","dort ","bes ","alti ","yedi ","sekiz ","dokuz ");	
$dondur = str_replace($sayi,$harf,$cevir);
return $dondur;
}


$Rakam = Donustur($_POST["rakam"]);
echo $Rakam;
?>