function nav_select_init( )
      {
        var box1    = getObject( 'br1' );
        var box2    = getObject( 'br2' );
        var box3    = getObject( 'br3' );

        if( !box1 ) return 0;
        optionTest = true;

        lgth = box1.options.length - 1;
        box1.options[lgth] = null;

        if( box1.options[lgth] ) { optionTest = false; }
        loadOptions2( box1, base1, 'init', index1 );
        if (!optionTest) return;

        box1.onchange = function( ) {
            loadOptions2( box2, base2, this.options[this.selectedIndex].value, index2 );
            if( box2.options.length && box3.options ) {
                loadOptions2( box3, base3, box2.options[box2.selectedIndex].value, index3 );
            }
        }
        box2.onchange = function( ) { loadOptions2( box3, base3, this.options[this.selectedIndex].value, index3 ); }

        if( box1.options[box1.selectedIndex].value ) { loadOptions2( box2, base2, box1.options[box1.selectedIndex].value, index2 ); }
        if( box2.options[box2.selectedIndex].value ) { loadOptions2( box3, base3, box2.options[box2.selectedIndex].value, index3 ); }
      }

    function loadOptions2( object, opts, index, sel_index )
      {
        if( object.options ) {
            for (var i=object.options.length; i >= 0 ;i-- ) { object.options[i] = null; }
            object.selectedIndex = -1;

            for( i=0; i < opts.length ;i+=1 ) {
                test = opts[i][0];
                test2 = opts[i][1];
                if( index == 'init' ) {
                    object.options[object.options.length] = new Option( opts[i][2], opts[i][1] );
                    if( test2 == sel_index ) { object.options[(object.options.length-1)].selected = true; }
                } else if( !test ) {
                    object.options[object.options.length] = new Option( opts[i][2], opts[i][1] );
                } else if( index ) {
                    if( test == index || test == '' ) {
                        object.options[object.options.length] = new Option( opts[i][2], opts[i][1] );
                        if( test2 == sel_index ) { object.options[(object.options.length-1)].selected = true; }
                    }
                }
            }
        }
      }


    window.onload = nav_select_init;