>>>Hi Viv,
>>>
>>>This doesn't seem to work for me. I am getting null being sent to the controller's method instead of the value I typed.
>>>
>>>Here is what I see when I inspect this element in Opera:
>>>
>>>

>>><div class="editor-field" style="background-color: rgb(242, 250, 237);">
>>><input class="text-box single-line valid" data-bind="value: Name" data-val="true" 
>>>data-val-remote="Client Name already exists. Please enter a different Client Name." 
>>>data-val-remote-additionalfields="*.Name" data-val-remote-type="POST" 
>>>data-val-remote-url="/Client/doesClientNameExist" 
>>>data-val-required="The Client Name field is required." id="Name" name="Client.Name" type="text" value=""/>ev
>>><span class="field-validation-valid" data-valmsg-for="Name" data-valmsg-replace="true"/>
>>>

>>>
>>>Could the problem be that the Id is "Name" but the name is "Client.Name"
>>>
>>>?
>>Don't know why id is "Client.Name" but make sure that the parameter name in the validation method exactly matches the control id. i.e.:

public JsonResult doesClientNameExist(string Name)
>>    {
>>    }

If it doesn't you will get null for sure....
>
>I have another question. I found that when I open the Edit form, the validation fire right away.
>
>I am not sure why does it happen and how to prevent it. Also, for the edit I only want to check for uniqueness if there is another id with the same client no.
>
>So, this is what I tried - in the Edit method (Get version) of the controller I set ViewBag.ClientID = id; and I changed my methods to be
>
>

>[HttpPost]
>        public JsonResult doesClientNoExist(Int16 Number)
>        {
>            bool result = false;
>            
>            if (ViewBag.ClientId !=null)
>
>            { 
>                int id = ViewBag.ClientId;
>                result= Db.Clients.Any(c => c.Number == Number && c.Id !=id);
>            }
>            else
>                result= Db.Clients.Any(c => c.Number == Number) ;
>
>            return Json((!result), JsonRequestBehavior.AllowGet);
>        }
>

>
>However, ViewBag.ClientId returns null and so immediately after I fire that form it comes up with the Client No aleady exists message.
>
>Do you see how can I solve this problem?
>
>Thanks in advance.

Bit hard to see where Number / ClientId comes from.

But if, for example, ClientId is a control on the form then you can use the 'AdditionalFields' property of the Remote attribute when validating the name. Something like:

[Remote("doesClientNameExist", "Account",AdditionalFields = "ClientId")]

and

   public JsonResult doesClientNameExist(string UserName, string ClientId)
    {
        //.......
    }

then you'll have both properties available. Don't know if this is what you were looking for tho :-{

Also, without looking more, I've no suggestions as to why the validation fires on keypress......