function checkPage()
{
	var email = document.forms[0].email.value;
	if(email==""){alert("Please enter your email address.");return;}
	var pos1 = email.indexOf("@");
	var pos2 = email.indexOf(".",pos1);
	if((pos1>0) && (pos2>pos1+1) && (email.length>pos2+1)) 
	{
		document.forms[0].submit();
	}
	else
	{
		alert("Please enter a vaild email address.");
	}
}