function endsWith(s, domain)
{
	var dl = domain.length;
	var sl = s.length;
	if (dl>sl) return false;

	if (s.substring(sl-dl)==domain) return true;
	
	return false;
}

function validEmail(s)
{
	var i,j;

	if ((i=s.indexOf('@'))<0) return false;
	if ((s.indexOf('@',i+1))>=0) return false;
	if ((j=s.lastIndexOf('.'))<0) return false;
	if (i==0) return false;
		if ((j-i)<2) return false;

	s=s.substring(j+1).toLowerCase();

	switch (s.length)
	{
		case 2:
				break;
		case 3:
		case 4:
				if ((s!='com')&&
					(s!='edu')&&
				  (s!='mil')&&
				  (s!='org')&&
				  (s!='net')&&
				  (s!='gov')&&
				  (s!='arpa')&&
				  (s!='int')&&
				  (s!='firm')&&
				  (s!='shop')&&
				  (s!='web')&&
				  (s!='arts')&&
				  (s!='rec')&&
				  (s!='info')&&
				  (s!='nom'))
				  	return false;
			break;
		default:
			return false;
	}

	return true;
}

function checkData()
{
	var s =myform.email.value;
	
	if (!validEmail(s))
	{
		alert("Please enter a correct email address\nof the form someone@somedomain.com");
		myform.email.focus();
		myform.email.select();
		return false;
	}
	return true;
}