Código PHP:
include "conexion.php";
if (!isset($accion)){
$result=mysql_query("SELECT * FROM clientes WHERE id=$id",$conexion);
if (mysql_num_rows($result) == 0) {
echo "ID inexistente";
} else {
$row=mysql_fetch_row($result);
echo"
<table width=100>
<tr>
<form action=\"delete2.php?accion=borrar\" method=\"POST\">
<b>Nombre:</b><br>...";
}