Need help removing child

Question

Sorry to bring problems but i am trying to learn some as3 and so far i can not resolve this situation ,,,,,,
this is the script i am using ,,,,,,,,,,,,,,
Ent.buttonMode = true;
Bio.buttonMode = true;
ent.addEventListener(MouseEvent.CLICK, goEnt);
function goEnt (e:MouseEvent):void
var new Ent:MovieClip = new firstIntro();
this.addChild(newEnt);
newEnt.x = 659;
newEnt.y = 428;
Bio.addEventListener(MouseEvent.CLICK, goBio);
function goBio (e:MouseEvent):void
var newBio:MovieClip = new bioIntro();
this.addChild(newBio);
newBio.x = 659;
newBio.y = 428;
the problem is that when i click on first button the Movie Clip does load ok but when i click on second button the first movie cliip is visible ,,,, i have try everything i have read here but no luck ,,,,,,, i want to learn how to remove first child and allow only the second child to show up ,,,,,,, i am looking forward to add more buttons so the remove child should be for multiple buttons ,,,,, i am learning and so far did purchase a online tutorial but did not help me with this situation ,,,, thank you all in advance ,,,,,

Answer 1

Create a variable to hold a reference to any child object that is added to the display list, then when any given button is used to add a new movieclip to the display list, use removeChild to get rid if any existing movie clip that was added through the reference in the variable. After the new movie clip is added to the display list, add a reference to that movie clip to the variable so that it can be used when the next movie clip will be added.
Ent.buttonMode = true;
Bio.buttonMode = true;
// create a variable to hold a reference to the currently added child, if any...
var currentChild: MovieClip;
ent.addEventListener(MouseEvent.CLICK, goEnt);
function goEnt (e:MouseEvent):void
var new Ent:MovieClip = new firstIntro();
// remove any child object currently in the display list...
if(currentChild != null) {
removeChild(currentChild);
this.addChild(newEnt);
// put a reference to the added child to the variable...
currentChild = newEnt;
newEnt.x = 659;
newEnt.y = 428;
Bio.addEventListener(MouseEvent.CLICK, goBio);
function goBio (e:MouseEvent):void
var newBio:MovieClip = new bioIntro();
// remove any child object currently in the display list...
if(currentChild != null) {
removeChild(currentChild);
this.addChild(newBio);
// put a reference to the added child to the variable...
currentChild = newBio;
newBio.x = 659;
newBio.y = 428;