function get_Button_display_style() {

    var list = document.styleSheets;

    // w3.css must be loaded first, so we get the correct rules here
    var rules = list[0].cssRules;

    for ( var i=0; i<rules.length; i++ ) {
        var text = rules[i].cssText;

        // XXX: much too complex code for getting the display: definition of
        // a css class

        // if it is the rule for w3-button
        if ( text.indexOf(".w3-button ") > -1 ) {
            //  which includes a display: definition
            if ( text.indexOf("display:") > 0 ) {
                // and is not part of the @media definition
                if ( text.indexOf("@media" ) == -1 ) {
                    // return display: definition
                    return rules[i].style.display;
                }
            }
        }
    }
}