function check_feedback()
{
	if (get_key('sent'))
	{
		show_hide('feedback_success_message', true);
		show_hide('feedback_form', false);
	}
	
	if (get_key('invalid'))
	{
		show_hide('feedback_invalid_message', true);
	}
}

function validate_form()
{
	valid_form = true;
	show_hide('feedback_invalid_message', false);
	
	company_name = document.forms.feedback_form.company_name;
	company_name.className = 'feedback';
	if (!company_name.value.length)
	{
		valid_form = false;
		company_name.className = 'feedback required';
	}
	
	email = document.forms.feedback_form.email;
	email.className = 'feedback';
	valid_email = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/; 
	if (!valid_email.test(email.value))
	{
		valid_form = false;
		email.className = 'feedback required';
	}

	contact_name = document.forms.feedback_form.contact_name;
	contact_name.className = 'feedback';
	if (!contact_name.value.length)
	{
		valid_form = false;
		contact_name.className = 'feedback required';
	}
	
	if (!valid_form)
	{
		show_hide('feedback_invalid_message', true);
	}

	return valid_form;
}

function reset_form()
{
	show_hide('feedback_invalid_message', false);
	document.forms.feedback_form.company_name.className = 'feedback';
	document.forms.feedback_form.email.className = 'feedback';
	document.forms.feedback_form.contact_name.className = 'feedback';
}

function get_key(find_key)
{
    get_value = false;
    get_string = location.search.substr(1);
	
	if (get_string.indexOf('&') > 0)
	{
		key_pairs = get_string.split('&');
	}
	else
	{
		key_pairs = new Array(get_string);
	}
    

    for (i = 0; i < key_pairs.length; i ++) 
    {
		if (key_pairs[i].indexOf('=') > 0)
		{			
			get_array = key_pairs[i].split('=');
			if (get_array[0] == find_key) 
			{
				get_value = get_array[1];
			}
		}
    }
	
    return get_value;
}

function show_hide(id, show)
{
	update_position = 'absolute';
	update_visibility = 'hidden';
	
	if (show)
	{
		update_position = 'relative';
		update_visibility = 'visible';
	}
	
	document.getElementById(id).style.visibility = update_visibility;
	document.getElementById(id).style.position = update_position;
}