On the Web Developer Toolbar there is an icon labeled "Information". Click it and then select "View Javascript".
Click on "Collapse All" then scroll to the last link and expand it. You should see the javascript code that is giving you problems - copy it.
Now open a new tab in Firefox and go to http://jsbeautifier.org/ and paste the code there. Check all the checkboxes and then submit.
At this point it should be clear to you that your php file is creating nested try{}catch() statements but ultimately is NOT closing them.
So, to fix the error you need to examine your php code. It seems that it is dynamically generating javascript from within some loop.
It should NOT be doing that from within a loop since:
a. it keeps sending code to validate the same fields over and over.
b. it is not sending the closing brace for your try (this is what the browser is complaining about).