Async a function with WebWorkers

HeavyWork.js

function HeavyWork(func, param, cb){
    if (window.Worker){
        var strFunc = 'onmessage = function(event) {' +
        '	postMessage((' + func.toString() + ')(event.data));' +
        '}';

        var blob = new Blob([strFunc], {type: 'application/javascript'});

        var work = new Worker(URL.createObjectURL(blob))

        work.onmessage = function(e) {
            cb(e.data);
        };

        work.postMessage(param);
    }
}

HeavyWork(function(a){
    console.log(a);
    return a + 1;
}, 1, function(b){
    console.log(b);
})