String.prototype.replaceMultiple = function( find, replace ) {
	
	var str = this;
	var indexOfFind = str.indexOf( find );

	while( indexOfFind != -1 ) {

		str = str.replace( find, replace );

		indexOfFind = str.indexOf( find );
	}

	return (str);
}

var isParticipantsAdded = false;
var participantsDefaultText;
var participants_start = 0;

$( document ).ready( function() {
	
	$( '#participants' ).change( function() {

		var participants_count = parseInt( $( this ).val() );

		if( participants_count == 0 ) {
			participants_start = 0;
			$( '#participants-grid' ).html( participantsDefaultText );
			$( '.participants-grid-error' ).show();
			isParticipantsAdded = false;
			return;
		} else {

			if( !isParticipantsAdded ) {
				participantsDefaultText = $( '#participants-grid' ).html();
				$( '.participants-grid-error' ).show();
			}
		}
		
		if( participants_count > participants_start ) {

			// Get participants block
			var participants_pattern = $( '#participants-pattern' ).html();
			$( '.participants-grid-error' ).hide();

			if( !isParticipantsAdded ) {

				$( '#participants-grid' ).html( '' );
				isParticipantsAdded = true;
			}

			for( var i = participants_start + 1; i <= participants_count; i++ ) {

				$( '#participants-grid' ).append( participants_pattern.replaceMultiple( 'xx', i ) );
			}

			participants_start = participants_count;
		} else {

			var participants = $( '#seminar-registration-form fieldset .participant' );
			for( var i = $( participants ).size()-1; i >= participants_count; i-- ) {

				$( participants ).eq( i ).remove();
			}
			participants_start = participants_count;
		}
	});

	$( "a[rel='external']" ).each( function() {

		$( this ).attr({ target : "_blank" });
	});
});