javascript表单验证-匹配电子邮件字段

这是我对电子邮件地址字段email1的表单验证-我需要做的是添加第二个验证-email1等于email2，如果不是，则会显示不同的警报消息。我试图补充：

if (f.email1.value != f.email2.value)
{
    customAlert ("email2",bnadd_msg_005);
    return (false);
}

但这对我不起作用。有什么见解吗

case "email1":
                        // Checking to make sure email field is on the form
                        if (typeof f.email1 != "undefined") 
                        {
                            if ((f.email1.value == "") && (f.sameAsShip.checked) )
                            {
                                customAlert ("email1",bnadd_msg_018);
                                if ((typeof TeaLeaf != "undefined") && (typeof TeaLeaf.Client != "undefined") && (typeof TeaLeaf.Client.tlAddEvent != "undefined") ) {
                                        var nVO = { ErrorMessage : bnadd_msg_018} 
                                        TeaLeaf.Event.tlAddCustomEvent(subtype, nVO);
                                    }
                                return false;
                            }
                            //Validate that email address has @ and .
                            if(f.email1 && ( f.email1.value != "" ) && (!editEmail(f.email1.value,'Email Address'))) 
                            {
                                return false;
                            }
                            if(addrType == atBill)
                            {


                                if(f.email1.value == "")
                                {
                                    customAlert ("email1",bnadd_msg_018);
                                    if ((typeof TeaLeaf != "undefined") && (typeof TeaLeaf.Client != "undefined") && (typeof TeaLeaf.Client.tlAddEvent != "undefined") ) {
                                        var nVO = { ErrorMessage : bnadd_msg_018} 
                                        TeaLeaf.Event.tlAddCustomEvent(subtype, nVO);
                                    }
                                    return false;
                                }
                                else
                                {
                                    if(f.email1 && ( f.email1.value != "" ) && (!editEmail(f.email1.value,'Email Address'))) 
                                    {
                                        return false;
                                    }
                                    else
                                        return true;    
                                }


                            }

                        }
                        break;

---

工作。感谢您对前面问题的帮助

case "email2":
                        // Checking to make sure email field is on the form
                        if (typeof f.email2 != "undefined") 
                        {
                            if ((f.email2.value != f.email1.value) && (f.sameAsShip.checked) )
                            {
                                customAlert ("email2",bnadd_msg_005);
                                if ((typeof TeaLeaf != "undefined") && (typeof TeaLeaf.Client != "undefined") && (typeof TeaLeaf.Client.tlAddEvent != "undefined") ) {
                                        var nVO = { ErrorMessage : bnadd_msg_018} 
                                        TeaLeaf.Event.tlAddCustomEvent(subtype, nVO);
                                    }
                                return false;
                            }
                            //Validate that email address has @ and .
                            if(f.email2 && ( f.email2.value != f.email1.value) && (!editEmail(f.email2.value,'Email Address'))) 
                            {
                                return false;
                            }
                            if(addrType == atBill)
                            {


                                if(f.email2.value != f.email1.value)
                                {
                                    customAlert ("email2",bnadd_msg_005);
                                    if ((typeof TeaLeaf != "undefined") && (typeof TeaLeaf.Client != "undefined") && (typeof TeaLeaf.Client.tlAddEvent != "undefined") ) {
                                        var nVO = { ErrorMessage : bnadd_msg_005} 
                                        TeaLeaf.Event.tlAddCustomEvent(subtype, nVO);
                                    }
                                    return false;
                                }
                                else
                                {
                                    if(f.email2 && (f.email2.value != f.email1.value) && (!editEmail(f.email1.value,'Email Address'))) 
                                    {
                                        return false;
                                    }
                                    else
                                        return true;    
                                }


                            }

                        }
                        break;