function validateEmailInput(btnSendMail) {
    var tbSendMail = getControl(btnSendMail, 'text');
    if (tbSendMail != null) {
        if (tbSendMail.value == 'sales@sochs.co.uk' || tbSendMail.value == '') {
            alert('Please specify an email for your friend');
            tbSendMail.focus();
            return false;
        }
        else {
            var re = new RegExp('^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$');
            if (!tbSendMail.value.match(re)) {
                alert('please specify a valid email');
                tbSendMail.focus();
                return false;
            }
        }
    }
    return true;
}