function checker()
{
for (var ink=1; ink<=4; ink++)
{
var sonder = /<|>|\||\;|:|#|\'|\+|\*|~|\\|\}|\=|\]|\)|\[|\(|\{|\/|\&|%|\$|§|³|\"|²/;
var find = sonder.exec(document.actionscript.elements[ink].value);
if(document.actionscript.elements[ink].value.indexOf(find) >= 0)
{
alert("Es sind nur _ - ! . ? , @ als Sonderzeichen erlaubt. - - - Only  _ - ! . ? , @ are allowed as special letters.");
document.actionscript.elements[ink].focus();
return false;
}
}

if(document.actionscript.name.value === "")
{
alert("Name wird benötigt.- - - Name required.");
document.actionscript.name.focus();
return false;
}

if(document.actionscript.email.value === "")
{
alert("E-Mail-Adresse wird benötigt.- - - E-mail adress required.");
document.actionscript.email.focus();
return false;
}

if(document.actionscript.email.value.indexOf('@') == -1)
{
alert("Ungültige E-Mail-Adresse! - - - Invalid E-mail adress.");
document.actionscript.email.focus();
return false;
}

if(document.actionscript.email.value.indexOf('.') == -1)
{
alert("Ungültige E-Mail-Adresse! - - - Invalid E-mail adress.");
document.actionscript.email.focus();
return false;
}

if((document.actionscript.email.value.lastIndexOf('.')) - (document.actionscript.email.value.indexOf('@')) < 4)
{
alert("Ungültige E-Mail-Adresse! - - - Invalid E-mail adress.");
document.actionscript.email.focus();
return false;
}

if(document.actionscript.guestbook_field)
{
if(document.actionscript.guestbook_field.value !== "")
{
if(document.actionscript.guestbook_field.value.indexOf('.') == -1)
{
alert("Keine gültige URL. - - - No valid URL.");
document.actionscript.guestbook_field.focus();
return false;
}
if(document.actionscript.guestbook_field.value.lastIndexOf('.') == document.actionscript.guestbook_field.value.indexOf('.'))
{
alert("Keine gültige URL. - - -No valid URL.");
document.actionscript.guestbook_field.focus();
return false;
}
if((document.actionscript.guestbook_field.value.lastIndexOf('.')) - (document.actionscript.guestbook_field.value.indexOf('.')) < 4)
{
alert("Keine gültige URL. - - - No valid URL.");
document.actionscript.guestbook_field.focus();
return false;
}
}
}

if(document.actionscript.contact_field)
{
if(document.actionscript.contact_field.value === "")
{
alert("Der Betreff fehlt. - - - What is your concern?");
document.actionscript.contact_field.focus();
return false;
}
}

if(document.actionscript.webmaster_field)
{
if(document.actionscript.webmaster_field.value === "")
{
alert("Der Betreff fehlt. - - - What is your concern?");
document.actionscript.webmaster_field.focus();
return false;
}
}

if(document.actionscript.message.value === "")
{
alert("Wollten Sie keine Nachricht schreiben? - - - Don't you want to send a message?");
document.actionscript.message.focus();
return false;
}
}