function isEmail(str){
	var objRegExp =  /^((?:(?:(?:(\w|~)[~\.\-\+]?)*)(\w|~))+)\@((?:(?:(?:\w[\.\-\+]?){0,62})\w)+)\.([a-zA-Z]{2,6})$|^$/;
	return objRegExp.test(str);
}  

function checkForm()
{	
	check = "true";

	errors = "Errors:\n";

	if (document.forms.newsletter.Newsletter[0].checked==false && document.forms.newsletter.Newsletter[1].checked==false)
	{
		errors += "--> Do you want to subscribe or unsubscribe the newsletter?\n";
		check = "false"; 
	}
	if (document.forms.newsletter.Name.value=="" || document.forms.newsletter.Name.value=="Name")
	{
		errors += "--> Please fill your Last Name\n";
		check = "false"; 
	}
	if (!isEmail(document.forms.newsletter.Email.value) || document.forms.newsletter.Email.value=="")
	{
		errors += "--> Please insert your correct Email-Adress\n";
		check = "false"; 
	}
	if (check=="false")
	{
		alert (errors);
	}
	else
	{
		document.forms.newsletter.submit();
	}
}