hola, ya encontre la solucion, (y para mas de una opcion xD ) si alguien lo googlea o algo la coloco
-----------------------------------------{filtro php}-------------------------------------------------
yamamos la variable 1 y 2 , condicionamos para que solo nos de el resultado que queremos y lo dividimos en condicionales para que no mande dos valores , junto con un else "muestra todos" por defecto
Cita: <? $ver1 = $_REQUEST['var1'];
$ver2 = $_REQUEST['var2'];
if ($ver1){
if ($ver1&&$ver1!='*') $condicion = "WHERE var1='$ver1' ";
else $condicion = "";
$sql = "SELECT * FROM $app $condicion ORDER BY var1 ASC";
$result = mysql_query($sql,$db_link) or die (mysql_error());}
if ($ver2){
if ($ver2&&$ver2!='*') $condicion = "WHERE var2='$ver2' ";
else $condicion = "";
$sql = "SELECT * FROM $app $condicion ORDER BY var2 ASC";
$result = mysql_query($sql,$db_link) or die (mysql_error());}
else {
$sql = "SELECT * FROM $app $condicion ORDER BY var1 ASC";
$result = mysql_query($sql,$db_link) or die (mysql_error());}?>
<form action='mequierobolverchango.php' method='post'>
<select name='var1' onchange='submit();'>
<OPTION selected>miko</OPTION>
<OPTION VALUE="*">Todos</OPTION>
<?$sql1 = "SELECT * FROM $app GROUP BY var1";
$result1 = mysql_query($sql1,$db_link) or die (mysql_error());
while ($row1=mysql_fetch_array($result1)){echo '<option>'.$row1['var1'];}?>
</select>
</form>
<form action='mequierobolverchango.php' method='post'>
<select name='var2' onchange='submit();'>
<OPTION selected>--mono--</OPTION>
<OPTION VALUE="*">Todos</OPTION>
<?$sql1 = "SELECT * FROM $app GROUP BY var2";
$result1 = mysql_query($sql1,$db_link) or die (mysql_error());
while ($row1=mysql_fetch_array($result1)){echo '<option>'.$row1['var2'];}?>
</SELECT>
</form>