function checkContactForm()
{
	var firstName = document.getElementById('first_name').value;
	var lastName = document.getElementById('last_name').value;
	var eMail = document.getElementById('email').value;
	
	if ( firstName.length==0 || lastName.length==0 || eMail.length==0 )
	{
		alert("You have to fill the required fields");
		return false;
	}  // if
	
	if ( (eMail.indexOf(".")>2) && (eMail.indexOf("@")>0) )
	{
		return true;
	}
	else
	{
		alert("You have to enter a valid email address");
		return false;
	} // if
	
} // doContact