function check_signup_data()
{
	var email = document.signup.email.value;
	var emailPat=/^(.+)@(.+)$/;
	var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
	var validChars="\[^\\s" + specialChars + "\]";
	var quotedUser="(\"[^\"]*\")";
	var atom=validChars + '+';
	var word="(" + atom + "|" + quotedUser + ")";
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
	var matchArray = email.match(emailPat);
	if (matchArray==null) 
	{
		alert("Email address seems incorrect (check @ and .'s)");
		document.signup.email.focus();
		return false
	}
	var user=matchArray[1];
	var domain=matchArray[2];
	if (user.match(userPat)==null) 
	{
		alert("Email address is invalid: " + email);
		document.signup.email.focus();
	    return false;
	}
	var domainArray=domain.match(domainPat)
	if (domainArray==null) 
	{
		alert("Email address is invalid.");
		document.signup.email.focus();
	    return false;
	}
	if (document.signup.confirm_email && document.signup.confirm_email.value != document.signup.email.value)
	{
                alert("Two email addresses do not match.");
                document.signup.email.focus();
            	return false;
	}
	if (document.signup.uid)
	{
		var uid = document.signup.uid.value;
		if (uid != '' && uid.match(userPat) == null) 
		{
			alert("Optional login ID is invalid.");
			document.signup.uid.focus();
	    		return false;	
		}
	}
	var pass1 = document.signup.pass1.value;
	var pass1_c = document.signup.pass1_c.value;
    if (pass1.length < 4)
    {
        alert("Please assign at least 4 characters for your password");
		document.signup.pass1.focus();
        return false;
    }
    if (pass1_c.length < 4)
    {
        alert("Please assign at least 4 characters for your password");
		document.signup.pass1_c.focus();
        return false;
    }
    if (pass1 != pass1_c)
    {
        alert("Two passwords do not match.");
        return false;
    }
	return true;
}

function check_use_uid(v)
{
	if (document.signup.use_uid.checked)
	{
		document.signup.uid.disabled = false;
	}
	else
	{
		document.signup.uid.disabled = true;
	}
}