True or better Random numbers with Javascript

I have all kinds of resources that rely on javascript random numbers. However, I've been seeing a lot of problems where random isn't so random because of the way I'm generating random numbers.

Is there any javascript resource for me to generate true, or just better random numbers?

I know that I can interface with Random.org, but what other options do I have?

I'm using:

function rand( lowest, highest){
    var adjustedHigh = (highest - lowest) + 1;       
    return Math.floor(Math.random()*adjustedHigh) + parseFloat(lowest);
}

Solution

Assuming you're not just seeing patterns where there aren't any, try a Mersenee Twister (Wikipedia article here). There are various implementations like this one on github.