There is something wrong with the formatting for the update method (this is different from what has already been mentioned). Look at the params option in the options object:
I think it might be just an issue with the "<" brackets in the source.
If tt>true any <>script> tags embedded in the response text will be extracted and executed. ....
Second, I think there are some options for the update method that appear to be missing. Just reviewing the example below the options, you can see discardUrl, nocache, text and scripts is missing. The indentation of the options that are present is not quite right too.
Third, there is a minor typo in the update example:
Fourth, take a look at the code in the Usage section at the very top of the Ext.Updater page. It has a line of code that looks like this:
scripts: false // Save time by avoiding RexExp execution.
It doesn't look like that parameter pattern is supported by the update docs. Either the example is wrong or the update method docs are missing something.