Question

I have this code:

<script id="toModify" >
Invalid javascript that will cause errors
</script>

<script>
var s=document.getElementById("toModify");
s.innerHTML="alert('Hi')";
</script>

And it doesn’t work.

I know there is at least two things I need to do so that it works:

• Prevent the first script to run the first time.
• Once modified, re-run the first script.

How can I do these things? Is there something else I need to do?

Answer 1

• Use a type attribute so that the browser doesn’t execute a script:

  <script id="toModify" type="text/x-custom-whatever">...</script>
  

• Just eval() the code to execute it.

Of course, dynamically generating code is fraught with peril; be very careful that you’re not introducing security holes.