function ValidateForm() {
	//Gather form elements
	var firstname = document.getElementsByName("First_Name");
	var lastname = document.getElementsByName("Last_Name");
	var organization = document.getElementsByName("Organization");
	var email = document.getElementsByName("E-mail");
	var seminar = document.getElementsByName("Seminar_To_Attend");
	
	//Validate form elements
	if(IsEmpty(firstname))
		return ErrorOut("Please enter your first name");
	if(IsEmpty(lastname))
		return ErrorOut("Please enter your last name");
	if(IsEmpty(organization))
		return ErrorOut("Please enter your organization");
	if(IsEmpty(email))
		return ErrorOut("Please enter your email address");
	
	if(!ValidateEmail(email[0].value))
		return ErrorOut("Please enter a valid email address");
		
	if(!ValidateSeminars(seminar))
		return ErrorOut("Please select at least one seminar to attend");

	return true;
}

function ValidateSeminars(seminars) {
	
	for(i = 0; i < seminars.length; i++) {
		if(seminars[i].checked == true)
			return true;
	}
	return false;
}

function ValidateEmail(email) {
	 var expr = "^[\\w-_\.]*[\\w-_\.]\@[\\w]\.+[\\w]+[\\w]$";
     var regex = new RegExp(expr);
     return regex.test(email);
}

function IsEmpty(input) {
	return input[0].value.length == 0;
}

function ErrorOut(error) {
	alert(error);
	return false;
}