I try to pass an Arraycollection to php.
To do that, I use this function:

```
  public function arrayCollectionToString( myArrayCollection:ArrayCollection ):String  
    {  
        var collStr:String = new String();  
        for each( var obj:Object in myArrayCollection )  
        {  
            collStr += "[";  
            var i:int=0;
            for each( var obj2:Object in obj )  
            {  i++;

                if(i==1){
                    collStr += obj2.toString();  

                }else{
                    collStr +=", "+ obj2.toString();  

                }
            }  
            collStr += "]";  
        }  
        return collStr;  
    }

```

This function transform arraycollection in string, but how to know in witch order key appear ? 
Or if it's not possible, how transmit keyname to php and split the string in php script to transform string into array?
Thanks