function validateEmail(address)
{
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
   if(reg.test(address) == false) 
   {
      return false;
   }

   return true;
}

function validate()
{
	var result = true;
	var fields = Array('error_name', 'error_mail', 'error_subject', 'error_message');
	
	for(var i in fields)
	{
		document.getElementById(fields[i]).innerHTML = '';
	}	

	if(document.getElementById('cf_name').value == '')
	{
		document.getElementById('error_name').innerHTML = '<div class="input_error"><div>Insert your name</div><span>&nbsp;</span></div>';
		result = false;		
	}

	if(!validateEmail(document.getElementById('cf_mail').value))
	{
		document.getElementById('error_mail').innerHTML = '<div class="input_error"><div>Insert valid e-mail</div><span>&nbsp;</span></div>';
		result = false;		
	}

	if(document.getElementById('cf_subject').value == '')
	{
		document.getElementById('error_subject').innerHTML = '<div class="input_error"><div>Insert your subject</div><span>&nbsp;</span></div>';
		result = false;		
	}
	
	if(document.getElementById('cf_message').value == '')
	{
		document.getElementById('error_message').innerHTML = '<div class="input_error"><div>Insert your message</div><span>&nbsp;</span></div>';
		result = false;		
	}	

	if(result)
	{
		document.cf_form.submit();
	}
}