function checkData() {
	if(document.getElementById('email').value == '')
	{
		alert('Please complete email field.');
		return false;
	}
	if(document.getElementById('name').value == '')
	{
		alert('Please complete name field.');
		return false;
	}
	if(document.getElementById('subject').value == '')
	{
		alert('Please complete subject field.');
		return false;
	}
	if(document.getElementById('message').value == '')
	{
		alert('Please complete message field.');
		return false;
	}
	return true;
}