function getRealDisplay(elem) {
        if (elem.currentStyle) {
                return elem.currentStyle.display
        } else if (window.getComputedStyle) {
                var computedStyle = window.getComputedStyle(elem, null )

                return computedStyle.getPropertyValue('display')
        }
}

function hide(el) {
        if (!el.getAttribute('displayOld')) {
                el.setAttribute("displayOld", el.style.display)
        }

        el.style.display = "none"
}

displayCache = {}

function isHidden(el) {
        var width = el.offsetWidth, height = el.offsetHeight,
                tr = el.nodeName.toLowerCase() === "tr"

        return width === 0 && height === 0 && !tr ?
                true : width > 0 && height > 0 && !tr ? false : getRealDisplay(el)
}

function toggle(el) {
        isHidden(el) ? show(el) : hide(el)
}


function show(el) {

        if (getRealDisplay(el) != 'none') return

        var old = el.getAttribute("displayOld");
        el.style.display = old || "";

        if ( getRealDisplay(el) === "none" ) {
                var nodeName = el.nodeName, body = document.body, display

                if ( displayCache[nodeName] ) {
                        display = displayCache[nodeName]
                } else {
                        var testElem = document.createElement(nodeName)
                        body.appendChild(testElem)
                        display = getRealDisplay(testElem)

                        if (display === "none" ) {
                                display = "block"
                        }

                        body.removeChild(testElem)
                        displayCache[nodeName] = display
                }

                el.setAttribute('displayOld', display)
                el.style.display = display
        }
}