prevent special characters to be entered in search input

<script>
( function( $ ) {
    $( document ).ready( function() {
        var searchInput = $( '.et_pb_s' );
        if ( searchInput.length ) {
            $( '.et_pb_s' ).keypress( function( event ) {
                var character = String.fromCharCode( event.keyCode );
                return isValid( character );
            } );

            function isValid( str ) {
                return !/[~`!@#$%\^&*()+=\-\[\]\\';,/{}|\\":<>\?]/g.test( str );
            }
        }
    } );
} )( jQuery );
</script>