Passing A Value To Server

Basic Web Form... A few text boxes and a checkbox - and a card reader...
The effect I want to accomplish is this:
The basic credit card fields are there and can be filled out. But if the
user swipes the card, I want to fill out the fields automatically and make
them read only. (So far I can do this.)
But I also want a checkbox to appear that indicates the card was swiped.
The user can clear the checkbox, re-enabling the fields so they can be
edited, but then I will no longer consider the data as being swiped. I want
the check box to disappear if they clear it.
Using server controls, if I create a checkbox, but make it not visible, then
it's not available at the client side to work with from client side code.
So I would need to send some flag back to the server to indicate a post back
and have the page re-rendered properly. But how do send info to the server
like that without having a visible control to attach the data to?
(Does this make any sense? Not sure if I'm explaining it well.)
Is there a way to send a value back to the server, in a postback, where the
data is not a property of a server control that's tracking viewstate? The
session object is only available on the server side right?
Any guidance here is appreciated. Thanks.
Jerryto send additional value to server , one commonly used method is
a HiddenControl (you will access it like Request.Forms["HiddenContrlName"]
from code behind)
or a TextBox Webcontrol with size 0 or attribute style='display:none' ..
But if the only purpose of post back is to display/check the checkbox ,
probabaly a better approach is to do the display/check in the client side
javascript ..
Instead of settign Visibility=False, you would just add an attribute to
make it hidden , but still available at client code
CheckBoxName.Attributes.Add("style='display:none'")
"Jerry Camel" wrote:

> Basic Web Form... A few text boxes and a checkbox - and a card reader...
> The effect I want to accomplish is this:
> The basic credit card fields are there and can be filled out. But if the
> user swipes the card, I want to fill out the fields automatically and make
> them read only. (So far I can do this.)
> But I also want a checkbox to appear that indicates the card was swiped.
> The user can clear the checkbox, re-enabling the fields so they can be
> edited, but then I will no longer consider the data as being swiped. I wa
nt
> the check box to disappear if they clear it.
> Using server controls, if I create a checkbox, but make it not visible, th
en
> it's not available at the client side to work with from client side code.
> So I would need to send some flag back to the server to indicate a post ba
ck
> and have the page re-rendered properly. But how do send info to the serve
r
> like that without having a visible control to attach the data to?
> (Does this make any sense? Not sure if I'm explaining it well.)
> Is there a way to send a value back to the server, in a postback, where th
e
> data is not a property of a server control that's tracking viewstate? The
> session object is only available on the server side right?
> Any guidance here is appreciated. Thanks.
> Jerry
>
>
Okay... I can have the checkbox on the form and available with 'Display:
None'...
But I can't seem to find the proper syntax to change the display state and
make it visible on the client side...
Thanks.
"Sreejith Ram" <SreejithRam@.discussions.microsoft.com> wrote in message
news:431FA795-5920-4B2C-81E1-98224CD89497@.microsoft.com...
> to send additional value to server , one commonly used method is
> a HiddenControl (you will access it like Request.Forms["HiddenContrlName"]
> from code behind)
> or a TextBox Webcontrol with size 0 or attribute style='display:none' ..
> But if the only purpose of post back is to display/check the checkbox ,
> probabaly a better approach is to do the display/check in the client side
> javascript ..
> Instead of settign Visibility=False, you would just add an attribute to
> make it hidden , but still available at client code
> CheckBoxName.Attributes.Add("style='display:none'")
>
> "Jerry Camel" wrote:
>
reader...
the
make
want
then
code.
back
server
the
The
Syntax to display ?
document.getElementById("CheckBoxClientName").style.display='' ;
document.getElementById("CheckBoxClientName").Checked = true;
this may help...
http://www.w3schools.com/htmldom/dom_obj_checkbox.asp
http://www.w3schools.com/htmldom/do...tyle.asp#layout
"Jerry Camel" wrote:

> Okay... I can have the checkbox on the form and available with 'Display:
> None'...
> But I can't seem to find the proper syntax to change the display state and
> make it visible on the client side...
> Thanks.
>
> "Sreejith Ram" <SreejithRam@.discussions.microsoft.com> wrote in message
> news:431FA795-5920-4B2C-81E1-98224CD89497@.microsoft.com...
> reader...
> the
> make
> want
> then
> code.
> back
> server
> the
> The
>
>
Thanks, but this doesn't seem to have any effect. I tried changing the
style.display property to all kinds of values, but the checkbox never
appears...
Jerry
"Sreejith Ram" <SreejithRam@.discussions.microsoft.com> wrote in message
news:514C006A-51EE-42B4-938C-506D452587A4@.microsoft.com...
> Syntax to display ?
> document.getElementById("CheckBoxClientName").style.display='' ;
> document.getElementById("CheckBoxClientName").Checked = true;
> this may help...
> http://www.w3schools.com/htmldom/dom_obj_checkbox.asp
> http://www.w3schools.com/htmldom/do...tyle.asp#layout
>
> "Jerry Camel" wrote:
>
'Display:
and
Request.Forms["HiddenContrlName"]
..
,
side
to
if
and
swiped.
be
I
visible,
post
where
viewstate?
Obviously there is some thing not right other than the syntax.. :) .. Is
there any javascript error when you call the function to display the
checkbox?...
if still no luck, you may want to create a simple HTML page with only
following code in it...
<INPUT TYPE=checkbox ID=chk1 style='display:hidden'>
<INPUT TYPE=button ID=btn1 onClick="toggle()" value="Click to Toggle
Display" >
<script>
function toggle(id)
{
el = document.getElementById("chk1");
var display = el.style.display ? '' : 'none';
el.style.display = display;
}
</script>
Once this works, you can compare with the HTML your aspx generated and that
may help in finding the issue..
This link got a working sample... with code...pls see if this helps..
http://www.sam-i-am.com/work/sandbo...le_display.html
"Jerry Camel" wrote:

> Thanks, but this doesn't seem to have any effect. I tried changing the
> style.display property to all kinds of values, but the checkbox never
> appears...
> Jerry
> "Sreejith Ram" <SreejithRam@.discussions.microsoft.com> wrote in message
> news:514C006A-51EE-42B4-938C-506D452587A4@.microsoft.com...
> 'Display:
> and
> Request.Forms["HiddenContrlName"]
> ...
> ,
> side
> to
> if
> and
> swiped.
> be
> I
> visible,
> post
> where
> viewstate?
>
>
I'll play with it. Thanks for your help. I was trying to use vbscript, but
I may have to switch to javascript...
Jerry
"Sreejith Ram" <SreejithRam@.discussions.microsoft.com> wrote in message
news:54BF5C69-C844-40FF-A427-409FEAED12EE@.microsoft.com...
> Obviously there is some thing not right other than the syntax.. :) .. Is
> there any javascript error when you call the function to display the
> checkbox?...
> if still no luck, you may want to create a simple HTML page with only
> following code in it...
> <INPUT TYPE=checkbox ID=chk1 style='display:hidden'>
> <INPUT TYPE=button ID=btn1 onClick="toggle()" value="Click to Toggle
> Display" >
> <script>
> function toggle(id)
> {
> el = document.getElementById("chk1");
> var display = el.style.display ? '' : 'none';
> el.style.display = display;
> }
> </script>
> Once this works, you can compare with the HTML your aspx generated and
that
> may help in finding the issue..
> This link got a working sample... with code...pls see if this helps..
> http://www.sam-i-am.com/work/sandbo...le_display.html
>
> "Jerry Camel" wrote:
>
document.getElementById("CheckBoxClientName").style.display='' ;
true;
state
message
style='display:none'
checkbox
client
attribute
But
automatically
can
swiped.
side
a
the
to?
postback,