textbod id changed automatically

Hi There,
I've a master page, and the content place i'v a page which has a text box
name tbCity. I would like to use javascript to find out that was blank or
not.
When i look at the sourcecode th text box id was chagned to
ctl00_Main_tbCity
why is it like this.
ThanksHello Ganesh

> I've a master page, and the content place i'v a page which has a text box
> name tbCity. I would like to use javascript to find out that was blank or
> not.
document.getElementById(<Control.ClientID> ).value == '';

> When i look at the sourcecode th text box id was chagned to
> ctl00_Main_tbCity
> why is it like this.
On the server side, ASP.NET has features like, nesting Controls, Namespaces,
etc..
that help to have consistente IDs. That means also, you can have more then
on of the same IDs on a page.
When ASP.NET rendered the code for viewing in a Html Browser, there are no
features like on the server side.
Here you can`t have more then one identic ID for a control.
So ASP.NET generates automatically IDs and Names where based on the control
hierarchy.
The <Control>.ClientID represents the ID Attribute on the clientside.
The <Control>.UniqueID represents the NAME Attribute on the clientside.
I have written a german article about identification of ASP.NET Controls.
Maybe you`r be able to understand the Google Translated Page:
-
http://translate.google.com/transla...aspnetzone.de/ - ASP.NET Zone, die ASP.NET Community
http://www.aspnetzone.de/blogs/peterbucher/ - Auf den Spuren von .NET
Hi Peter,
Thanks for your help.
"Peter Bucher [MVP]" <peter.bucher@.aspnetzone.de> wrote in message
news:OxXvYyf0HHA.1184@.TK2MSFTNGP04.phx.gbl...
> Hello Ganesh
>
> document.getElementById(<Control.ClientID> ).value == '';
>
> On the server side, ASP.NET has features like, nesting Controls,
> Namespaces, etc..
> that help to have consistente IDs. That means also, you can have more then
> on of the same IDs on a page.
> When ASP.NET rendered the code for viewing in a Html Browser, there are no
> features like on the server side.
> Here you can`t have more then one identic ID for a control.
> So ASP.NET generates automatically IDs and Names where based on the
> control hierarchy.
> The <Control>.ClientID represents the ID Attribute on the clientside.
> The <Control>.UniqueID represents the NAME Attribute on the clientside.
> I have written a german article about identification of ASP.NET Controls.
> Maybe you`r be able to understand the Google Translated Page:
> -
> http://translate.google.com/transla...aspnetzone.de/ - ASP.NET Zone, die ASP.NET Community
> http://www.aspnetzone.de/blogs/peterbucher/ - Auf den Spuren von .NET
"Ganesh" <gsganesh@.yahoo.com> wrote in message
news:OO75qTf0HHA.1100@.TK2MSFTNGP06.phx.gbl...

> I've a master page, and the content place i'v a page which has a text box
> name tbCity. I would like to use javascript to find out that was blank or
> not.
> When i look at the sourcecode th text box id was chagned to
> ctl00_Main_tbCity
if (document.getElementById(<%=tbCity.ClientID%> ).value == '')
{
// do something
}

> why is it like this.
To guarantee uniqueness of ID.
Mark Rae
ASP.NET MVP
http://www.markrae.net