function toggleSub(submenu) {
    if (document.getElementById(submenu).style.display == 'none') {
        document.getElementById(submenu).style.display = 'block'
    } else {
        document.getElementById(submenu).style.display = 'none'
    }
}

function DisplayMail(Server, Login, Display, Alt){   
    if ((Display.length == 0) || (Display.indexOf('@')+1)) {   
    document.write('<a hr' + 'ef=' + '"mai' + 'lto:' + Login + '@' + Server + '"' + Alt + '>' + Login + '@' + Server + '<\/a>'); }   
    else  {   
    document.write('<a hr' + 'ef=' + '"mai' + 'lto:' + Login + '@' + Server + '"' + Alt + '>' + Display + '<\/a>'); }   
}   

function checkElements() {
var z = document.forms["paring"];
var nimi = z.elements.nimi.value;
var email = z.elements.email.value;
var tel = z.elements.tel.value;

var error_1 = "Palun sisestage nimi!";
var error_2 = "Palun sisestage e-posti aadress!";
var error_3 = "Palun sisestage korrektne e-posti aadress!";
var error_4 = "Palun sisestage kontakttelefon!";

if (nimi == "") 
        {
         alert(error_1); 
        return false;
        } 
                
if (email == "") 
        {
         alert(error_2); 
        return false;
        } 

if (z.elements.email.value.indexOf("@")==-1 || z.elements.email.value.indexOf(".")==-1 || z.elements.email.value.length<6) {
alert(error_3);
return false;
}

if (tel == "") 
        {
         alert(error_4); 
        return false;
        } 
}