Please see here: http://www.wunderwedding.com/weddingvenues/search

On the left side there's a filter 'show more cities...'

When it's clicked I want to show more cities. But right now when it's clicked the box expands and IMMEDIATELY collapses again. I dont know what Im doing wrong. This is the code for show/hide:

$("#toggle_cities").click(function () {
    if ($("#facets_city").is(":visible")) {
        $("#toggle_cities").text('toon meer steden...');
    }
    else {
        $("#toggle_cities").text('toon minder steden...');
    }
    $("#facets_city").slideToggle("slow");
});