When you click the above button, a new window will be opened to execute the code in the TextArea.
Because i just think that the TinyMCE editor does not support the form element well in article, I change the default editor to FCKEditor now.
And add relative javascript function into the template's base js file.
So, insert a textarea which id is "jsta", and add the button, which onclick function is "runcode();".
Now it is working.
