jQuery.fn.monoShow = function(speed, callback) {
    if(typeof speed != 'undefined') {
       return this.fadeIn(speed, function() {
        if (jQuery.browser.msie)
            this.style.removeAttribute('filter')
        if (typeof callback == 'function')
            callback()
       })
    }
    else {
        this.fadeIn('normal', function() {
            if (jQuery.browser.msie)
                this.style.removeAttribute('filter')
        })
    }
}

jQuery.fn.toggleVisibility = function() {
    if (this.css('visibility') == 'hidden') {
        this.css('visibility', 'visible')
    } else {
        this.css('visibility', 'hidden')
    }
}