Código PHP:
<?php
echo "<form action='form_envio_whats.php' method=post>";
echo "\n<table align=center>";
echo "\n<tr><td><b>Nombre</b></td><td><b>Teléfono</b></td></tr>";
$i = 1;
while ($fila=mysql_fetch_array($result)){
echo "\n<input type=hidden name='id_cap$i' value='" . $fila["id_cap"] . "'>";
echo "<tr>";
echo "<td>" . $fila["id_cap"] . "</td>";
echo "<td>" . $fila["nombre"] . "</td>";
if($fila['leido'] == 'No'){
echo "<td><input type=text name='leido$i' value='" . $fila["leido"] . "'></td>";
echo "<td><input type=text name='phone$i' value='" . $fila["phone"] . "'></td>";
echo "<td>" ?><a href="whatsapp://send?text=Hola <?php echo '' . $fila["nombre"].'' ?> ! <?php
echo '' . $mensaje .'' ?>&phone=<?php echo '' . $fila["phone"] . '' ; ?>&abid=+<?php echo '' . $fila["phone"] .'' ; ?>" > Enviar Whatsapp </a><?php
}
echo "</tr>";
$ultimo_mostrado = $fila["id_cap"];
}
echo "\n <td colspan=2 align=right><input type='submit' value='Editar todos'></td></td></tr>";
echo "\n</table>";
echo "\n</form>";
?>
ahi va