Object sort

i am sorting an arrayCollection and then adding the sorted collection as object variables.But the object is getting sorted by default in the ascending order of the variable name

for eg i have a collection like this coll[{[6]:30},{[4]:39},{[8]:45},{[5]:50}] which is sorted in ascending order of the values.

i want to add this name value pair to an object
var obj:Object=new Object()
for(var i:int=0;i<coll.length().i++)
{
obj[coll[0].name]=coll[0].value

}
But the object gets sorted in ascending order based on the name
like this obj[4]
obj[5]
obj[6] and so on
How can i display the object variables in the order they were added.