Retrieve the CRM Organization URL with respect to the current domain name. For example, if you are browsing the CRM instance with IP, then the return value would be like this: http(s)://<IP>/<OrgName>If you are browsing with domain name, it would be like this: http(s)://<DomainName>/<OrgName> 

function GetServerUrlRegExp(location) {
    var urlReg = new RegExp(/http[s]?://[0-9.:]+/[^/]+/);
    var ServerUrl = Xrm.Page.context.getServerUrl();
    if (window.location.href.match(urlReg) != null) {
        ServerUrl = window.location.href.match(urlReg).toString();
    }
    if (ServerUrl.match(//$/)) {
        ServerUrl = ServerUrl.substring(0, ServerUrl.length - 1);
    }
    return ServerUrl;
}

SOURCE : JUST2CODE.IN