function loadCSS(browserName, cssName, browserVersion, condition, browserVersion2) {

    var expresion;

    switch (browserName) {
        case "Firefox":
            expresion = browserName + "[\/\s](\\d+\.\\d+)";
            break;
        case "IE":
            expresion = "MSIE (\\d+\.\\d+);";
            break;      
    }

    var reg = new RegExp(expresion, "g");
    var matches = reg.exec(navigator.userAgent);
   
    if (matches != null) {

        var version = new Number(matches[1]);
        var condExpresion;

        if (condition != null) {
            if (condition == "betwen") {
                condition = (version >= browserVersion) && (version <= browserVersion2);
            }
            else {
                condition = "version " + condition + " browserVersion";
            }
            if (eval(condition)) {
                writeCss(cssName);
                return true;
            }
        }
        else {
            writeCss(cssName);
            return true;
        }
    }    
    
    return false;   
}

function writeCss(cssName) {
    var fileref = document.createElement("link")
    fileref.setAttribute("rel", "stylesheet")
    fileref.setAttribute("type", "text/css")
    fileref.setAttribute("href", cssName)
    document.getElementsByTagName("head")[0].appendChild(fileref)
}