function createStyleRule(selector, declaration) {
    if (!document.getElementsByTagName || !(document.createElement || document.createElementNS)) return;
    var agt = navigator.userAgent.toLowerCase();
    var is_ie = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
    var is_iewin = (is_ie && (agt.indexOf("win") != -1));
    var is_iemac = (is_ie && (agt.indexOf("mac") != -1));
    if (is_iemac) return; // script doesn't work properly in IE/Mac
    var head = document.getElementsByTagName("head")[0];
    var style = (typeof document.createElementNS != "undefined") ? document.createElementNS("http://www.w3.org/1999/xhtml", "style") : document.createElement("style");
    if (!is_iewin) {
        var styleRule = document.createTextNode(selector + " {" + declaration + "}");
        style.appendChild(styleRule); // bugs in IE/Win
    }
    style.setAttribute("type", "text/css");
    style.setAttribute("media", "screen");
    head.appendChild(style);
    if (is_iewin && document.styleSheets && document.styleSheets.length > 0) {
        var lastStyle = document.styleSheets[document.styleSheets.length - 1];
        if (typeof lastStyle.addRule == "object") { // bugs in IE/Mac and Safari
            lastStyle.addRule(selector, declaration);
        }
    }
}

/*	DOM manipulation functions;
Can only be used after a page has fully loaded
*/

function setElementStyleById(id, propertyName, propertyValue) {
    if (!document.getElementById) return;
    var el = document.getElementById(id);
    if (el) el.style[propertyName] = propertyValue;
}

function setElementStyle(element, propertyName, propertyValue) {
    if (!document.getElementsByTagName) return;
    var el = document.getElementsByTagName(element);
    for (var i = 0; i < el.length; i++) {
        el[i].style[propertyName] = propertyValue;
    }
}

function setElementStyleByClassName(cl, propertyName, propertyValue) {
    if (!document.getElementsByTagName) return;
    var re = new RegExp("(^| )" + cl + "( |$)");
    var el = document.all ? document.all : document.getElementsByTagName("body")[0].getElementsByTagName("*"); // fix for IE5.x
    for (var i = 0; i < el.length; i++) {
        if (el[i].className && el[i].className.match(re)) {
            el[i].style[propertyName] = propertyValue;
        }
    }
}