Properties of objects can be accessed via square brackets, similar to indexes in an array.
Each property name (the variable name) is actually a variable key.
It is also recommended to CHECK that the object actually HAS the property, using the Object.hasOwnProptery(propertyName:String) method.
http://help.adobe.com/en_US/AS2LCR/Flash_10.0/help.html?content=00001424.html
Example:
for(var i:uint = 1; i < 15; i++){
if (this["a"+i].x== this["q"+i].x ){
points= points+1;
}
else{
this["q"+i].visible=false;
// shows the good answer
}
}
I have not checked, but it may be wise to use Number instead of uint and toString to retrieve it's string value when creating the variable name