execution of some code inside javascript function

Question

I have a div with some example code in it. I'd like to execute this code after pressing a button. Here's what I've tried:

HTML

<button onclick="javascript:playcode()"> </button>

JS

function playcode () {
 var execcode= "";
 for (i=1; i<=countCodeLine (); i++)
 execcode += document.getElementById("line"+i).innerText;
 var div= document.getElementById ("mydiv");
 var scr= document.createElement ('script', "");
 div.innerHTML= "play() {"+execcode+"}";
 div.appendChild(scr);
 play();
}

but it doesn't work. How can i do this?

UPDATE: here the errors from the console:

(line 9: pre.appendChild(scr)) Uncaught SyntaxError: Unexpected token { 
(line 10: play()) Uncaught TypeError: object is not a function 

• Chris Dixon: Do you get any errors in your console?
• Thilo: what does not work? Do you get any errors? (You don't need the named jump label javascript: btw if you don't use break or things like that).
• edi9999: There's no reason this doesn't work, except if the onclick attribute was changed or the javascript not loaded.
• Damian0o: Include all HTML code ...
• Justin L.: it looks like you could just use an eval here to get the exact functionality.

Answer 1

If you are indeed getting the right HTML into execcode, you can use

eval(execcode);

You can check this by just doing a simple console.log(execcode) or alert(execcode) to verify that it's loaded correctly.

However, I can guarantee you that this is almost certainly a very, very bad idea. it'd be trivial for someone to just edit your DOM and insert whatever malicious javascript they want.

• Justin L.: you're welcome, but remember that you probably shouldn't do this in a production environment.