var I = 'ip';
var msg = 'Valid IP required!';
var msg_genuine = 'Average volume of genuine required';
var msg_isp = 'ISP name required';

IP = document.getElementById('LINE'+I);
genuine = document.getElementById('LINEgenuine');
spam = document.getElementById('LINEspam');
isp = document.getElementById('LINEisp');
server = document.getElementById('LINEserver');
F = document.forms['khs_require'] || document.forms['khs_trial_require'];

function IsChecked(v){ return document.getElementById('interest_'+v).checked }
function SetVis2(){ if(IP) IP.style.display = IsChecked(2) ? '':'none' }
function SetVis1(){
        ch = IsChecked(1) ? '':'none';
        if(genuine) genuine.style.display = ch;
        if(spam) spam.style.display = ch;
        if(isp) isp.style.display = ch;
        if(server) server.style.display = ch;
}
function Check(){
        if(IsChecked(2)){
                for(var i = 1; i < 5; i++){
                        var n = document.getElementById(I + '_' + i);
                        if(!n) next;
                        if(n.value == '' || n.value > 255){
                                alert(msg);  return false
                        }
                }
        }
        if(IsChecked(1)){
                if(!F.genuine.value.length){    alert(msg_genuine);     return false }
                if(!F.isp.value.length){                alert(msg_isp);         return false }
        }
        return true
}

document.getElementById('interest_1').onclick = SetVis1;
document.getElementById('interest_2').onclick = SetVis2;
SetVis1();
SetVis2();
if(F) F.onsubmit = Check;