var gArr = [6, 9, 5, 3, 8, 5, 10, 35, 1, 99, 2];
var gLowest4ValuesArr = GetLowestValuesArr(gArr, 4);

function GetLowestValuesArr(array, valuesRequired){
    // clone array so we don't upset order in the original
    var cloneArr = new Array(array.length);
    for(var i in array){
        cloneArr[i] = array[i];
    }

    // sort the cloned array & return the required number of values
    cloneArr.sort();
    var valuesToReturn = Math.min(cloneArr.length, valuesRequired);
    var retVal = new Array(valuesToReturn);
    for(var i = 0; i < valuesToReturn; i++){
        retVal[i] = cloneArr[i];
    }
    return retVal;
}

cloneArr.sort(SortNums);

...

function SortNums(a, b){
    return a - b;
}