function bookmark(href, text){
  if(window.external && typeof (window.external.AddFavorite) == 'function')
  {
     window.external.AddFavorite(href, text);
     return false;
  } else {
     alert('Niestety twoja przeglądarka nie udostępnia możliwości dodania bookmarku z poziomu Javascript.\n Wciśnij na klawiaturze CTRL+D w celu dodania strony do bookmarków.');
	 return false;	
  }
} 

  function chkLine() {
     var friend1 = document.getElementById('author1');
     var friend_email1 = document.getElementById('email1');
     var friend_line1 = document.getElementById('data1');
     var friend2 = document.getElementById('author2');
     var friend_email2 = document.getElementById('email2');
     var friend_line2 = document.getElementById('data2');
     var friend3 = document.getElementById('author3');
     var friend_email3 = document.getElementById('email3');
     var friend_line3 = document.getElementById('data3');
     var friend4 = document.getElementById('author4');
     var friend_email4 = document.getElementById('email4');
     var friend_line4 = document.getElementById('data4');
     var friend5 = document.getElementById('author5');
     var friend_email5 = document.getElementById('email5');
     var friend_line5 = document.getElementById('data5');
     var friend6 = document.getElementById('author6');
     var friend_email6 = document.getElementById('email6');
     var friend_line6 = document.getElementById('data6');
     var friend7 = document.getElementById('author7');
     var friend_email7 = document.getElementById('email7');
     var friend_line7 = document.getElementById('data7');
     var friend8 = document.getElementById('author8');
     var friend_email8 = document.getElementById('email8');
     var friend_line8 = document.getElementById('data8');
     var text = '';
     if (friend_email8.value.length > 0 ) {
     	checkValidation(friend_email8.value, 'e-mail dla ósmego znajomego');
	 }
     if (friend7 && friend_email7 && friend8 && friend_email8 && friend_line8) {
          text = friend7.value + friend_email7.value;
          if (text.length > 0) {
              friend_line8.style.display = "";
          } else {
              friend_line7.style.display = "none";
/*              friend8.value = "";
              friend_email8.value = ""; */
          }
          if (friend_email7.value.length > 0 ) {
			checkValidation(friend_email7.value, 'e-mail dla siódmego znajomego');
		  }
     }
     if (friend6 && friend_email6 && friend7 && friend_email7 && friend_line7) {
          text = friend6.value + friend_email6.value;
          if (text.length > 0) {
              friend_line6.style.display = "";
          } else {
              friend_line7.style.display = "none";
/*              friend7.value = "";
              friend_email7.value = ""; */
          }
          if (friend_email6.value.length > 0 ) {
			checkValidation(friend_email6.value, 'e-mail dla szóstego znajomego');
		  }
     }
     if (friend5 && friend_email5 && friend6 && friend_email6 && friend_line6) {
          text = friend5.value + friend_email5.value;
          if (text.length > 0) {
              friend_line6.style.display = "";
          } else {
              friend_line5.style.display = "none";
/*              friend6.value = "";
              friend_email6.value = ""; */
          }
          if (friend_email5.value.length > 0 ) {
			checkValidation(friend_email5.value, 'e-mail dla piątego znajomego');
		  }
     }
     if (friend4 && friend_email4 && friend5 && friend_email5 && friend_line5) {
          text = friend4.value + friend_email4.value;
          if (text.length > 0) {
              friend_line5.style.display = "";
          } else {
              friend_line4.style.display = "none";
/*              friend5.value = "";
              friend_email5.value = ""; */
          }
          if (friend_email4.value.length > 0 ) {
			checkValidation(friend_email4.value, 'e-mail dla czwartego znajomego');
		  }
     }
     if (friend3 && friend_email3 && friend4 && friend_email4 && friend_line4) {
          text = friend3.value + friend_email3.value;
          if (text.length > 0) {
              friend_line4.style.display = "";
          } else {
              friend_line3.style.display = "none";
/*              friend4.value = "";
              friend_email4.value = ""; */
          }
          if (friend_email3.value.length > 0 ) {
			checkValidation(friend_email3.value, 'e-mail dla trzeciego znajomego');
		  }
     }
     if (friend2 && friend_email2 && friend3 && friend_email3 && friend_line3) {
          text = friend2.value + friend_email2.value;
          if (text.length > 0) {
              friend_line3.style.display = "";
          } else {
              friend_line2.style.display = "none";
/*              friend3.value = "";
              friend_email3.value = ""; */
          }
          if (friend_email2.value.length > 0 ) {
			checkValidation(friend_email2.value, 'e-mail dla drugiego znajomego');
		  }
     }
     if (friend1 && friend_email1 && friend2 && friend_email2 && friend_line2) {
          text = friend1.value + friend_email1.value;
          if (text.length > 0) {
              friend_line2.style.display = "";
          } else {
              friend_line1.style.display = "none";
/*              friend2.value = "";
              friend_email2.value = ""; */
          }
          if (friend_email1.value.length > 0 ) {
			checkValidation(friend_email1.value, 'e-mail dla pierwszego znajomego');
		  }
     }
  }
  
  
  
  
  
  
 function checkValidation ( addressField, name ) {
    if ( stringEmpty ( addressField ) )
        alert ( "Błąd! Nie został wprowadzony adres e-mail w polu " + name );
    else if ( noAtSign ( addressField ) )
        alert ( "Błąd! W adresie e-mail z pola " + name + " brakuje znaku '@'" );
    else if ( nothingBeforeAt ( addressField) )
        alert ( "Błąd! W adresie e-mail z pola " + name + " powinien wystąpić przynajmniej jeden znak przed znakiem '@'" );
    else if ( noLeftBracket ( addressField ) )
        alert ( "Błąd! W adresie e-mail z pola " + name + " występuje nawias ']',\n lecz brakuje nawiasu otwierającego '['" );
    else if ( noRightBracket ( addressField ) )
        alert ( "Błąd! W adresie e-mail z pola " + name + " występuje nawias '[',\n lecz brakuje nawiasu zamykającego ']'" );
    else if ( noValidPeriod ( addressField ) )
        alert ( "Błąd! W adresie e-mail z pola " + name + " powinien wystąpić znak '.'" );
    else if ( noValidSuffix ( addressField ) )
        alert ( "Błąd! Adres e-mail z pola " + name + " powinien zawierać dwu lub trzy literowy suffix np. pl" );
    else
        return (true);

    return ( false );
}

function stringEmpty ( address ) {
    // CHECK THAT THE STRING IS NOT EMPTY
    if ( address.length < 1 ) {
        return ( true );
    } else {
        return ( false );
    }
}

function noAtSign ( address ) {
    // CHECK THAT THERE IS AN '@' CHARACTER IN THE STRING
    if ( address.indexOf ( '@', 0 ) == -1 ) {
        return ( true )
    } else {
        return ( false );
    }
}

function nothingBeforeAt ( address ) {
    // CHECK THERE IS AT LEAST ONE CHARACTER BEFORE THE '@' CHARACTER
    if ( address.indexOf ( '@', 0 ) < 1 ) {
        return ( true )
    } else {
        return ( false );
    }
}

function noLeftBracket ( address ) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN CHECK FOR LEFT BRACKET
    if ( address.indexOf ( '[', 0 ) == -1 && address.charAt ( address.length - 1 ) == ']' ) {
        return ( true )
    } else {
        return ( false );
    }
}

function noRightBracket ( address ) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN CHECK FOR RIGHT BRACKET
    if ( address.indexOf ( '[', 0 ) > -1 && address.charAt ( address.length - 1 ) != ']' ) {
        return ( true );
    } else {
        return ( false );
    }
}

function noValidPeriod ( address ) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN WE ARE NOT INTERESTED
    if ( address.indexOf ( '@', 0 ) > 1 && address.charAt ( address.length - 1 ) == ']' )
        return ( false );

    // CHECK THAT THERE IS AT LEAST ONE PERIOD IN THE STRING
    if ( address.indexOf ( '.', 0 ) == -1 )
        return ( true );

    return ( false );
}

function noValidSuffix ( address ) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN WE ARE NOT INTERESTED
    if ( address.indexOf ( '@', 0 ) > 1 && address.charAt ( address.length - 1 ) == ']' )
        return ( false );

    // CHECK THAT THERE IS A TWO OR THREE CHARACTER SUFFIX AFTER THE LAST PERIOD
    var len = address.length;
    var pos = address.lastIndexOf ( '.', len - 1 ) + 1;
    if ( ( len - pos ) < 2 || ( len - pos ) > 3 ) {
        return ( true );
    } else {
        return ( false );
    }
}