...este es solo el codigo de prueba...
Código PHP:
<?php
require("../Querys/conexion.php");
if((($_POST['email1'])!="")&&(($_POST['email2'])!="")&&(($_POST['email3'])!="")&&(($_POST['contrasenaingreso'])!="")){
$emailquery1 = mssql_query("SELECT email1 from usuarios WHERE email1 = '{$_POST['email1']}'");
$emailquery2 = mssql_query("SELECT email2 from usuarios WHERE email2 = '{$_POST['email2']}'");
$emailquery3 = mssql_query("SELECT email3 from usuarios WHERE email3 = '{$_POST['email3']}'");
$contrasenaquery = mssql_query("SELECT contraseña from usuarios WHERE contraseña = '{$_POST['contrasenaingreso']}'");
if((mssql_num_rows($emailquery1)==true)&&(mssql_num_rows($emailquery2)==true)&&(mssql_num_rows($emailquery3)==true)&&(mssql_num_rows($contrasenaquery))==true){
echo"Login correcto"; }else{echo"No se ha encontrado el registro";};}else{echo"Login fallido, Error3: 'campo(s) vacio(s)' ";};
?>