Yeah Moynul, that's one way to do it, but if you want smoother results try this:
stage.addEventListener(Event.ENTER_FRAME,stage_x);
function stage_x(e:Event){
var distance:Number = char.x-((stage.stageWidth/2)+offset);
var ease:int = 5;
var offset:int=10;
if(distance<0){
distance*=-1;
}
if(char.x<(stage.stageWidth/2)){
var variable:int=distance/ease;
ground.x+=variable;
char.x+=variable;
}
if(char.x>(stage.stageWidth/2)){
var variable2:int=distance/ease;
ground.x-=variable2;
char.x-=variable2;
}
}
The main character's instance name is the standard "char". This code will allow the "camera" view to ease to the player's location.