Function setting

Question

I wrote a dozen of simular functions like below, the bolded word can be anything like velocity, scale, ect...
function velocityGen() {
    velocityArray.splice(0, velocityArray.length-1);
    for (var i:int = 0; i<count; i++) {
        velocity = Math.random() * velocityRandomConstant + velocityConstant;
        velocityArray.push(velocity);
so I tried to extract the "keyword" of those functions to make a new and global function to do such simular jobs,
function valueGen(target:String) {
    this[target+"Array"].splice(0, this[target+"Array"].length-1);
    for (var i:int = 0; i<duskCount; i++) {
        this[target] = Math.random() * this[target+"RandomConstant"]+ this[target+"Constant"];
        this[target+"Array"].push(this[target]);
valueGen(velocity);
valueGen(blahblahblah);
of course I failed, here is the error message:
Scene 1, Layer 'actions', Frame 1, Line 196    1067: Implicit coercion of a value of type Number to an unrelated type String.
line 196 is the line "valueGen(velocity);" on above
Could anyone provide a correct sample for me? thz a lot
(ps. also I would like to know somemore details of the usage of "this", thz again)

Answer 1

that's the reason the compiler complained.  but you needed that message because velocity is a variable name and very different from the string "velocity".  if velocity were a string:
var velocity:String="HI";
the compiler wouldn't complain but you wouldn't be happy with your function call using velocity instead of "velocity".