Test for IE legacy Filters and Transitions support

detectIEfiltersupport.js

/*
    Test if this install of IE supports legacy Filters and Transitions

    Needed because Filters and Transitions can be disabled under IE's security 
    settings ("Binary and Script Behaviors" under the "ActiveX controls and 
    plug-ins" category). This is often done on corporate windows installations 
    "for security reasons". They'll fail silently (or error if you try to access
    the element's filter collection in js). This setting also disables VML.

    See: 
    http://paintincode.blogspot.co.uk/2012/06/css-opacity-ie-filter-binary-and-script.html

    Returns true if it detects support, false if not.
*/
function detectIEfiltersupport () {
    var supportsIEfilters = false, 
        el = document.body.appendChild(document.createElement("div")), 
        probe = 0;

    /* Try to set a filter on the div, then access the div's filters collection. 
       IE throws an error here if filters are disabled, so supportsIEfilters will
       remain false. */
    try {
        el.style.filter = "progid:DXImageTransform.Microsoft.Alpha(opacity=50)";
        probe = el.filters.length;
        supportsIEfilters = true;
    } catch (err) {
        /* In legacy IE, err will be "Unspecified error" if filters are disabled. Newer browsers 
           shouldn't have an el.filters so it'll be a reference error (undefined). */
        /* console.log("Error: ", err); */
    }

    el.parentNode.removeChild(el);
    return supportsIEfilters;
}