102
votes

Why doesn't the following work for me?

<script>
    document.getElementById('lbltipAddedComment').innerHTML = 'Your tip has been submitted!';
</script>
<label id="lbltipAddedComment"></label>
8
oops! sorry that should be 'doesnt' ;0phil crowe
Because when you script try to change label innerHtml, lbltipAddedComment actually not present at page. Insert script after label or use jquery $(document).ready()Andrew Orsich
sorry didnt see the edit button!phil crowe
i tried everything suggested here but nothing worked for me.Rajan Mishra

8 Answers

148
votes

Because your script runs BEFORE the label exists on the page (in the DOM). Either put the script after the label, or wait until the document has fully loaded (use an OnLoad function, such as the jQuery ready() or http://www.webreference.com/programming/javascript/onloads/)

This won't work:

<script>
  document.getElementById('lbltipAddedComment').innerHTML = 'your tip has been submitted!';
</script>
<label id="lbltipAddedComment">test</label>

This will work:

<label id="lbltipAddedComment">test</label>
<script>
  document.getElementById('lbltipAddedComment').innerHTML = 'your tip has been submitted!';
</script>

This example (jsfiddle link) maintains the order (script first, then label) and uses an onLoad:

<label id="lbltipAddedComment">test</label>
<script>
function addLoadEvent(func) {  
      var oldonload = window.onload;  
      if (typeof window.onload != 'function') {  
        window.onload = func;  
      } else {  
        window.onload = function() {  
          if (oldonload) {  
            oldonload();  
          }  
          func();  
        }  
      }  
    }  

   addLoadEvent(function() {  
document.getElementById('lbltipAddedComment').innerHTML = 'your tip has been submitted!';

    });  
</script>
24
votes

Have you tried .innerText or .value instead of .innerHTML?

17
votes

Because a label element is not loaded when a script is executed. Swap the label and script elements, and it will work:

<label id="lbltipAddedComment"></label>
<script>
    document.getElementById('lbltipAddedComment').innerHTML = 'Your tip has been submitted!';
</script>
11
votes

Use .textContent instead.

I was struggling with changing the value of a label as well, until I tried this.

If this doesn't solve try inspecting the object to see what properties you can set by logging it to the console with console.dir as shown on this question: How can I log an HTML element as a JavaScript object?

10
votes

Using .innerText should work.

document.getElementById('lbltipAddedComment').innerText = 'your tip has been submitted!';
8
votes

Here is another way to change the text of a label using jQuery:

<script>
  $("#lbltipAddedComment").text("your tip has been submitted!");
</script>

Check the JsFiddle example

1
votes

Try this:

<label id="lbltipAddedComment"></label>
<script type="text/javascript"> 
      document.getElementById('<%= lbltipAddedComment.ClientID %>').innerHTML = 'your tip has been submitted!';
</script>
0
votes

Because the script will get executed first.. When the script will get executed, at that time controls are not getting loaded. So after loading controls you write a script.

It will work.