disable button

when file is uploaded set RadButton.visible = false

thank you for replying... I am disabling the RadButton unless user clicked RadUpload's Select button and selected a file to upload.. basically, I need to check if there is a file shows on that textbox's of the RadUpload

ok but this is not RadUpload, it is regular input type .. file.. cant I do that with RadUpload?

used second link.. I get this error
Microsoft JScript runtime error: 'FileInputField.value' is null or not an object

function myOnClientFileSelected(radUpload, eventArgs)
{

        var selectedFileName = eventArgs.FileInputField.value.toLowerCase();  <---gives error when page loads because no file name  selected yet...
        if(selectedFileName != null)
        {
        btnUpload.disabled = "false";
        }
       
}

Check for null value like below


function myOnClientFileSelected(radUpload, eventArgs)
{
if(eventArgs != null && eventArgs.FileInputField != null)
{
        var selectedFileName = eventArgs.FileInputField.value.toLowerCase();  <---gives error when page loads because no file name  selected yet...
        if(selectedFileName != null)
        {
        btnUpload.disabled = "false";
        }
}

       
}

I did and nothing happening.. my button still disabled... something not right.. here my code... I made btnUpload enabled = false at the beginning so made that enabled true...below..

function myOnClientFileSelected(RadUpload, eventArgs) {

    alert("hi");
      if(eventArgs != null && eventArgs.FileInputField != null)
        {
            var selectedFileName = eventArgs.FileInputField.value.toLowerCase();
            if(selectedFileName != null)
            {
            btnUpload.enabled = "true";
            }
        }      
}

Instead of
".enabled=false"
use
".disabled=true"

and when condition is satisfied change it to
".disabled=false"

instead of below code

btnUpload.enabled = "true";

write

$('#btnUpload').attr("disabled", false);

or

$('#btnUpload").removeAttribute("disables");

you need to call jquery latest javascrit file in head section

I used this  $('#btnUpload").removeAttribute("disabled");  says Unterminated string constraint

would this be easier if we use visible ... true/false....

how will I get the latest javascript thing..? no idea...

bad combination of single quotes and double quotes.
try this:
$('#btnUpload').removeAttribute('disabled');

tried this says object not supported..$('#btnUpload').attr("disabled", false);

Microsoft JScript runtime error: Object doesn't support this property or method after your last comment..

If you are not using jQuery, the line above would be (I think, I'm not actually testing this as I type):

document.getElementById("btnUpload").removeAttribute("disabled");

Microsoft JScript runtime error: 'document.getElementById(...)' is null or not an object

Also could try this:
btnUpload.removeAttribute('disabled');

or this:
var thisButton = document.getElementById("btnUpload");
thisButton.removeAttribute('disabled');

(Sorry to be spammy with answers... it depends on what you have declared where and whether those things are in scope or not, etc.)

Perhaps the issue is your button is id="RadButton" and not "btnUpload" as the previous answers all suggest.

no it is btnUpload and I keep getting null value as of the the button, tried your last ex. I get object null error
<telerik:RadButton ID="btnUpload" runat="server" Text="Upload"
        onclick="btnUpload_Click"  Enabled="false">

only reason to get that error is that the Id does not match.
When you view source (or inspect w/ Firebug, etc.), what is the button's Id?

<table>
  <tr>
    <td>
         <telerik:RadUpload ID="RadUpload1" runat="server" Width="245px" InitialFileInputsCount="1"
        MaxFileInputsCount="1" AllowedFileExtensions=".jpg, .tif"  OnClientFileSelected="myOnClientFileSelected">
    </telerik:RadUpload>
     
    </td>
    <td valign="top">
       <telerik:RadButton ID="btnUpload" runat="server" Text="Upload"
        onclick="btnUpload_Click"  Enabled="false">
    </telerik:RadButton>
    </td>
  </tr>
</table>

here my full code for this...so it is called btnUpload I have no idea why it is null

this is in master page.. maybe that's why?

found this answer but dont actually know how to implement that because when I put this function on the master page, it complains because I dont have button like that...
http://stackoverflow.com/questions/5886617/disable-button-on-masterpage-net-4-0-c

What does "View Source" show for the element you are trying to enable?

JavaScript runs on the client, not the server.
To debug the JavaScript error, it is best to look at the rendered code - what you see when you "View Source".  Once you see what the error is, you can then either adjust your server side code to make it match what your JS is trying to do or change your JS to match what your server-side code is creating.

I am attaching view source.. I have even tried this without master page still getting null value for my btnUpload.... arrgghhh.. drives me crazy.
test.txt

figured it out different by just adding <div> and control that way.. Thank you all for trying to help!