function duffLoop(iterations) {

    var testVal=0;

    // Begin actual Duff's Device
    // Original JS Implementation by Jeff Greenberg 2/2001

    var n = iterations / 8;
    var caseTest = iterations % 8;    

    do {
        switch (caseTest)
        {
        case 0: [modify testVal here];
        case 7: [ditto];
        case 6: [ditto];
        case 5: [ditto];
        case 4: [ditto];
        case 3: [ditto];
        case 2: [ditto];
        case 1: [ditto];
        }
        caseTest=0;
    }
    while (--n > 0);
}