function check_email(email) {
	if( email.match(".+@.+\..+") ) return true;
	return false;
}

function check_pass_str(pass) {
	if( pass.match(/^\w+$/) ) return true; else return false;
}

function login_form_check(){
	if( document.form_login.email.value == "" ){
		alert( "Please enter your e-mail address.");
		return false;
	}

	if( !check_email(document.form_login.email.value) ){
		alert( "" + document.form_login.email.value + " is an invalid character string for an e-mail address.");
		return false;
	}

	if( document.form_login.pass.value == "" ){
		alert( "Please enter your password.");
		return false;
	}

	if( !check_pass_str( document.form_login.pass.value )){
		alert( "You may only use letters and numbers for you password.");
		return false;
	}
	
	if(location.href.match('ref=([a-z0-9_]+)')){
		document.form_login.done.value = RegExp.$1;
	}
	
	return true;
}

function set_signup_ref(){
	if(location.href.match('ref=([a-z0-9_]+)')){
		var a = document.getElementById('signup_link');
		if(a){
			a.href = a.href +'&ref=' + RegExp.$1;
		}
	}
}
function alert_keep_login()
{
	if (document.form_login.keep_login.checked)
	{
		alert("**　Please note　**\n\nIf this setting is processed, when a third party user who use this computer will be logined in automatically.");
	}
}

window.onload = set_signup_ref;