function zn_form_empty(){
    if(document.forms["zn_new"].email.value=='vase@adresa.cz')document.forms["zn_new"].email.value='';
}
function isEmail2(who) {
	var email=/^[A-Za-z0-9][\w-.]+[A-Za-z0-9]@[A-Za-z0-9]([\w-.]+[A-Za-z0-9]\.)+([A-Za-z]){2,4}$/i;
    return(email.test(who));
}
function zn_submit() {
if(isEmail2(document.zn_new.email.value)&&(!(document.zn_new.email.value=='vase@adresa.cz'))){document.zn_new.submit();}else{	alert('Zadejte prosím e-mailovou adresu!');}
}
function hide_emaily() {
    myemaily=document.getElementById('emaily');
    myhide=document.getElementById('hide');
    myshow=document.getElementById('show');
    myemaily.style.display='none';
    myhide.style.display='none';
    myshow.style.display='';
}
function show_emaily() {
    myemaily=document.getElementById('emaily');
    myhide=document.getElementById('hide');
    myshow=document.getElementById('show');
    myemaily.style.display='';
    myhide.style.display='';
    myshow.style.display='none';
}