Generate uniform (normal distributed) random numbers. Taken from http://www.protonfish.com/random.shtml

normalRandom.js

/** 
 * Generates normally distributed random numbers
 */
function normalRandom(mean, stdDev) {
    // Generate a "close enough" uniform random 
    // number w. mean = 0 and std.dev = 1
    var uniformRandom = (Math.random()*2-1)+(Math.random()*2-1)+(Math.random()*2-1);
    
    return Math.round(uniformRandom * stdDev + mean);
}