// Validate contact us form
function ValidateContactUs(frm)
{
	with(frm)
    {
    	if(!IsEmpty(first_name, 'Please, enter your first name.'))
        {
			return false;
        }
    	if(!IsEmpty(last_name, 'Please, enter your last name.'))
        {
			return false;
        }
    	if(!IsEmpty(email, 'Please, enter email address.'))
        {
			return false;
        }
		if(!IsEmail(email, 'Please, enter valid email address.'))
		{
			return false;
		}
        return true;
    }
}