find matching curly brackets - takes into account that it might hit strings yay (from dev_tools chrome source)

gistfile1.js

findBalancedCurlyBrackets: function(source, startIndex, lastIndex) {
        lastIndex = lastIndex || source.length;
        startIndex = startIndex || 0;
        var counter = 0;
        var inString = false;

        for (var index = startIndex; index < lastIndex; ++index) {
            var character = source[index];
            if (inString) {
                if (character === "\\")
                    ++index;
                else if (character === "\"")
                    inString = false;
            } else {
                if (character === "\"")
                    inString = true;
                else if (character === "{")
                    ++counter;
                else if (character === "}") {
                    if (--counter === 0)
                        return index + 1;
                }
            }
        }
        return -1;
    },