>>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.