Comment appeler une fonction d'une autre page?

<?php

function photosannonces($id){


$sql6 = "SELECT url_pho1 FROM annonces WHERE id_ann='$id'";
$query6 = @mysql_query($sql6);
$result6 = $query6;
}




if ($sql = "SELECT url_pho1 FROM annonces WHERE id_ann ='$id'" != '')
         

echo <img src=\"$photosannonces\" fct_affich_image(80, 60, \'$photosannonces\') >


         }

    else



{...


?>