A question about validator!
 

I am new on asp.net programming.
Here I got a problem about validator
I want to write a login.aspx page, for example, there is UserName box. I
need to validate two things on UserName box,
1. It must be filled. If it is empty, I will show a red message right
after
this box, like "UserName is empty!"
2. It must be a valid user in our database. So on server side, we will
check
this UserName in our database. If it is not in our database, we will show
something like "Invalid user name..."
I know it is very easy to do the 1st rule with the RequireFieldValidator.
But in order to do the rule 2, I need to put a Lable at the same place
where
the validator is. Right? But the two won't stay at the same place. So I
tried
to use a CustomValidator, and write the ClientValidationFunction like
this:
<script language="javascript">
function ValidUserName(oSrc, args) //For rule 1
{
if(args.Value.length > 0)
args.IsValid = true;
else
args.IsValid = false;
}
</script>
And also, I have a server validate function which will process the rule 2.
But the problem is the client validate function never get called. So , do
you guys have better solution for this? I really appreciated.

Re: A question about validator!
 

Thenk you peter!

"Peter Blum" wrote:

> When you need to do a database lookup to validate, do not use client-side
> validation at all. Database lookups are a feature of ASP.NET, not the
> browser. So use your customvalidator without the ClientValidationFunction
> but with the server side validation method doing all of the work.
>
> As a rule, all validation should work fully on the server side. Client-side
> validation is an optimization but is not available when the user turns off
> javascript or using any browser that does not support DHTML. (IE and IE/Mac
> are DHTML browsers; Mozilla and its kin are not.)
>
> So in your Click event handler method, always test Page.IsValid is true
> before proceeding.
>
> If you need client-side validation support on more than just DHTML browsers,
> use my solution: "Professional Validation And More"
> (http://www.peterblum.com/vam/home.aspx)
>
> --- Peter Blum
> www.PeterBlum.com
> Email: PLBlum@PeterBlum.com
> Creator of "Professional Validation And More" at
> http://www.peterblum.com/vam/home.aspx
>
> "Nicky" <Nicky@discussions.microsoft.com> wrote in message
> news:7EF004AE-D959-416C-9061-7F1FA2289D42@microsoft.com...
> >I am new on asp.net programming.
> > Here I got a problem about validator
> > I want to write a login.aspx page, for example, there is UserName box. I
> > need to validate two things on UserName box,
> > 1. It must be filled. If it is empty, I will show a red message right
> > after
> > this box, like "UserName is empty!"
> > 2. It must be a valid user in our database. So on server side, we will
> > check
> > this UserName in our database. If it is not in our database, we will show
> > something like "Invalid user name..."
> > I know it is very easy to do the 1st rule with the RequireFieldValidator.
> > But in order to do the rule 2, I need to put a Lable at the same place
> > where
> > the validator is. Right? But the two won't stay at the same place. So I
> > tried
> > to use a CustomValidator, and write the ClientValidationFunction like
> > this:
> > <script language="javascript">
> > function ValidUserName(oSrc, args) //For rule 1
> > {
> > if(args.Value.length > 0)
> > args.IsValid = true;
> > else
> > args.IsValid = false;
> > }
> > </script>
> > And also, I have a server validate function which will process the rule 2.
> > But the problem is the client validate function never get called. So , do
> > you guys have better solution for this? I really appreciated.
> >
>
>
>