function external_url() {
    if (!document.getElementsByTagName) return;
    var links = document.getElementsByTagName("a");
    for (var i=0; i<links.length; i++) {
        var thisLink = links[i];
        if (thisLink .getAttribute("href") && thisLink .getAttribute("class") == "external-link")
            thisLink .target = "_blank";
    }
    if(document.getElementById('selector')) {
        document.getElementById('selector').style.display='';
    }
}
function fadeIn(element) {
	document.getElementById(element).style.display='block';
}
function fadeOut(element) {
	document.getElementById(element).style.display='none';
}