I'm trying to read the errors in the console log & then do something if a particular error is thrown that says 'Script error.'

The following is some code I've pulled together and some commented pseudo code:

2. function errorHandle() {
3.     window.onerror = function(error, url, line, column, errorObj) {
4.       alert('Error: '+error+' Script: '+url+' Line: '+line+' Column: '+column+' StackTrace: '+errorObj);
5.       return true;
6.     };
7.   }
8.   // Then use a try/catch block to handle it
9.   try {
10.     errorHandle();
11.   } catch (e) {
12.       if (e != "") {
13.         alert('Errors: ' + e);
14.         var myerrors = e; //pseudo code
15.         // If e contains 'Script error.' then do something
16.         if (e.indexOf("Script error.") != -1) {
17.           alert('Script error was found');
18.         }
19.       }
20.   }

Thanks for the help.