function validate_login(x) {
	if (x.username.value.length < 4) {
		alert("Please enter a Username");
		x.username.focus();
		return false;
	}

	if (x.passwd.value.length < 4) {
		alert("Please enter a password");
		x.passwd.focus();
		return false;
	}
	return true;
}

function validate_register(x) {
		// validates the registration form
		if (x.fullname.value == "" || x.fullname.value.length == 0) {
			alert("Please enter your full name");
			x.fullname.focus();
			return false;
		}

	if (x.email.value == "" || x.email.value.length < 4) {
			alert("Please enter an email");
			x.email.focus();
			return false;
		}

	var email = x.email.value.match(/([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+)/gi);

		    if(!email) {
		     alert("Email Format incorrect. Please enter a valid Email Address");
		     x.email.focus();
			return false;
		}

		if (x.institution.value == "" || x.institution.value.length ==0) {
			alert("Please fill in your institution");
			x.institution.focus();
			return false;
		}	

		if (x.username.value == "" || x.username.value.length < 4) {
			alert("Please enter a username with 4 or more characters");
			x.username.focus();
			return false;
		}

		if (x.passwd.value == "" || x.passwd.value.length < 4) {
			alert("Please enter a password with 4 or more characters");
			x.passwd.focus();
			return false;
		}

		if (x.passwd2.value == "" || x.passwd2.value.length < 4) {
			alert("Please verify your password");
			x.passwd2.focus();
			return false;
		}

		if (x.passwd.value != x.passwd2.value) {
			alert("Your passwords do not match");
			x.passwd.value="";
			x.passwd2.value="";
			x.passwd.focus();
			return false;
		}

		// check that conditions have been agreed to
		if(!x.conditions.checked) {
			alert("Please read and agree to the copyright statement.");
			x.conditions.focus();
			return false;
		}
		return true;
}