gistfile1.js

// Stops people putting in Invalid nameservers
var nameserver = /^((([a-z0-9]([a-z0-9\-]{0,61}[a-z0-9])?\.)+[a-z]{2,6})|(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}))$/i;
$('#configure_domains_form').submit(function() {
        if (validNameserver($('input[name="domainns1"]')) && validNameserver($('input[name="domainns2"]')) && validNameserver($('input[name="domainns3"]')) &&
validNameserver($('input[name="domainns4"]'))){
                return true;
        }else{
                return false;
        }
});
                
function validNameserver(ns) {
        if(!nameserver.test(ns.val())){
          	if (ns.val() == ""){
                        if(ns.attr("name") == "domainns3" || ns.attr("name") == "domainns4"){
                                // Do nothing, it's ok for these to be Blank
                                return true;
                        }
                        else{
                                ns.addClass("errorbox");
                                alert(ns.attr("name") + ": Cannot be blank - you need 2 Nameservers. If in doubt, please use ns1.krystal.co.uk and ns2.krystal.co.uk");
                                return false;
                     	}
                }else{
                 	ns.addClass("errorbox");
                        alert(ns.val() + " is not a valid nameserver : " + ns.attr("name"));
                        return false;
                }
        }
        ns.removeClass("errorbox");
        return true;
}