diff --git a/sso.php b/sso.php
index 85bd023..3e3b7bb 100644
--- a/sso.php
+++ b/sso.php
@@ -7,88 +7,99 @@
  * License URI: http://www.gnu.org/licenses/gpl-2.0.html
  */
 
-function sso_check() {
-	if ( ! isset( $_GET['salt'] ) || ! isset( $_GET['nonce'] ) ) {
-		sso_req_login();
-	}
-	if ( sso_check_blocked() ) {
-		sso_req_login();
-	}
-
-	$nonce = esc_attr( $_GET['nonce'] );
-	$salt  = esc_attr( $_GET['salt'] );
-	$has_epoch = preg_match('/-e(\d+)$/', $nonce, $epoch);
-	$expired = ( $has_epoch && (time() - $epoch[1]) > 300 ) ? true : false;
-
-	if ( ! empty( $_GET['user'] ) ) {
-		$user = esc_attr( $_GET['user'] );
-	} else {
-		$user = get_users( array( 'role' => 'administrator', 'number' => 1 ) );
-		if ( is_array( $user ) && is_a( $user[0], 'WP_User' ) ) {
-			$user = $user[0];
-			$user = $user->ID;
-		} else {
-			$user = 0;
+ if( ! function_exists( 'sso_check' ) ){
+	function sso_check() {
+		if ( ! isset( $_GET['salt'] ) || ! isset( $_GET['nonce'] ) ) {
+			sso_req_login();
 		}
-	}
-
-	$bounce = ! empty( $_GET['bounce'] ) ? $_GET['bounce'] : '';
-	$hash   = base64_encode( hash( 'sha256', $nonce . $salt, false ) );
-	$hash   = substr( $hash, 0, 64 );
-
-	$token = get_transient( 'sso_token' );
-	$from_options = false;
-	if ( $token === false ) {
-		$token = get_option( 'sso_token' );
-		$from_options = true;
-	}
-	if ( ! $expired && $token == $hash ) {
-		if ( is_email( $user ) ) {
-			$user = get_user_by( 'email', $user );
+		if ( sso_check_blocked() ) {
+			sso_req_login();
+		}
+	
+		$nonce = esc_attr( $_GET['nonce'] );
+		$salt  = esc_attr( $_GET['salt'] );
+		$has_epoch = preg_match('/-e(\d+)$/', $nonce, $epoch);
+		$expired = ( $has_epoch && (time() - $epoch[1]) > 300 ) ? true : false;
+	
+		if ( ! empty( $_GET['user'] ) ) {
+			$user = esc_attr( $_GET['user'] );
 		} else {
-			$user = get_user_by( 'id', (int) $user );
+			$user = get_users( array( 'role' => 'administrator', 'number' => 1 ) );
+			if ( is_array( $user ) && is_a( $user[0], 'WP_User' ) ) {
+				$user = $user[0];
+				$user = $user->ID;
+			} else {
+				$user = 0;
+			}
 		}
-		if ( $from_options ) {
-			delete_option( 'sso_token' );
+	
+		$bounce = ! empty( $_GET['bounce'] ) ? $_GET['bounce'] : '';
+		$hash   = base64_encode( hash( 'sha256', $nonce . $salt, false ) );
+		$hash   = substr( $hash, 0, 64 );
+	
+		$token = get_transient( 'sso_token' );
+		$from_options = false;
+		if ( $token === false ) {
+			$token = get_option( 'sso_token' );
+			$from_options = true;
 		}
-		if ( is_a( $user, 'WP_User' ) ) {
-			wp_set_current_user( $user->ID, $user->user_login );
-			wp_set_auth_cookie( $user->ID );
-			do_action( 'wp_login', $user->user_login, $user );
-			delete_transient( 'sso_token' );
-			wp_safe_redirect( admin_url( $bounce ) );
+		if ( ! $expired && $token == $hash ) {
+			if ( is_email( $user ) ) {
+				$user = get_user_by( 'email', $user );
+			} else {
+				$user = get_user_by( 'id', (int) $user );
+			}
+			if ( $from_options ) {
+				delete_option( 'sso_token' );
+			}
+			if ( is_a( $user, 'WP_User' ) ) {
+				wp_set_current_user( $user->ID, $user->user_login );
+				wp_set_auth_cookie( $user->ID );
+				do_action( 'wp_login', $user->user_login, $user );
+				delete_transient( 'sso_token' );
+				wp_safe_redirect( admin_url( $bounce ) );
+			} else {
+				sso_req_login();
+			}
 		} else {
+			sso_add_failed_attempt();
 			sso_req_login();
 		}
-	} else {
-		sso_add_failed_attempt();
-		sso_req_login();
+		die();
 	}
-	die();
-}
+ }
+
 
 add_action( 'wp_ajax_nopriv_sso-check', 'sso_check' );
 add_action( 'wp_ajax_sso-check', 'sso_check' );
 
-function sso_req_login() {
-	wp_safe_redirect( wp_login_url() );
+if( ! function_exists( 'sso_req_login' ) ){
+	function sso_req_login() {
+		wp_safe_redirect( wp_login_url() );
+	}
 }
 
-function sso_get_attempt_id() {
-	return 'sso' . esc_url( $_SERVER['REMOTE_ADDR'] );
+if( ! function_exists( 'sso_get_attempt_id' ) ){
+	function sso_get_attempt_id() {
+		return 'sso' . esc_url( $_SERVER['REMOTE_ADDR'] );
+	}
 }
 
-function sso_add_failed_attempt() {
-	$attempts = get_transient( sso_get_attempt_id(), 0 );
-	$attempts ++;
-	set_transient( sso_get_attempt_id(), $attempts, 300 );
+if( ! function_exists( 'sso_add_failed_attempt' ) ){
+	function sso_add_failed_attempt() {
+		$attempts = get_transient( sso_get_attempt_id(), 0 );
+		$attempts ++;
+		set_transient( sso_get_attempt_id(), $attempts, 300 );
+	}
 }
 
-function sso_check_blocked() {
-	$attempts = get_transient( sso_get_attempt_id(), 0 );
-	if ( $attempts > 4 ) {
-		return true;
-	}
+if( ! function_exists( 'sso_check_blocked' ) ){
+	function sso_check_blocked() {
+		$attempts = get_transient( sso_get_attempt_id(), 0 );
+		if ( $attempts > 4 ) {
+			return true;
+		}
 
-	return false;
-}
+		return false;
+	}
+}
\ No newline at end of file