function validateForm()
{	
	var result = true;

	//get form fields
	var name = document.getElementById("fName");
	var email = document.getElementById("fEmail");
	var message = document.getElementById("fMessage");
	
	//clear all errors
	document.getElementById("error_name").style.visibility = "hidden";
	document.getElementById("error_email").style.visibility = "hidden";
	document.getElementById("error_message").style.visibility = "hidden";
	
	//validate name
	if(name.value.length == 0)
	{
		document.getElementById("error_name").style.visibility = "visible";
		result = false;
	}
	//validate email
	var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
	if(reg.test(email.value) == false) 
	{      
		document.getElementById("error_email").style.visibility = "visible";
		result = false;
	}
	//validate message
	if(message.value.length == 0)
	{
		document.getElementById("error_message").style.visibility = "visible";
		result = false;
	}
	
	return result;
}