How do I add to this dynamically {menu1:{url:['a.swf']}}

I dont know what this is called so I dont really know what to ask…

What I was hoping to do was something similar to this code below but dont know the syntax to update it dynamically.

 ActionScript Code:
 [FONT=Courier New][LEFT]sub = [COLOR=#000000]{[/COLOR]menu1:[COLOR=#000000]{[/COLOR][COLOR=#0000ff]url[/COLOR]:[COLOR=#000000][[/COLOR][COLOR=#ff0000]'this.swf'[/COLOR][COLOR=#000000]][/COLOR], targ:[COLOR=#000000][[/COLOR][COLOR=#ff0000]'my_mc'[/COLOR][COLOR=#000000]][/COLOR][COLOR=#000000]}[/COLOR], menu2:[COLOR=#000000]{[/COLOR][COLOR=#0000ff]url[/COLOR]:[COLOR=#000000][[/COLOR][COLOR=#ff0000]'this2.swf'[/COLOR][COLOR=#000000]][/COLOR], targ:[COLOR=#000000][[/COLOR][COLOR=#ff0000]'my_mc2'[/COLOR][COLOR=#000000]][/COLOR][COLOR=#000000]}[/COLOR][COLOR=#000000]}[/COLOR];

[COLOR=#0000ff]trace[/COLOR]COLOR=#000000[/COLOR]; [COLOR=#808080]*//traces my_mc2 *[/COLOR]

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Ive thought of two methods but neither work

eg1 ActionScript Code:
[FONT=Courier New][LEFT]sub = [COLOR=#000000]{[/COLOR][COLOR=#000000]};[/COLOR]
sub.[COLOR=#0000ff]push[/COLOR][COLOR=#000000]([/COLOR]menu1:[COLOR=#000000]{[/COLOR][COLOR=#0000ff]url[/COLOR]:[COLOR=#000000][[/COLOR][COLOR=#ff0000]‘this.swf’[/COLOR][COLOR=#000000]][/COLOR], targ:[COLOR=#000000][[/COLOR][COLOR=#ff0000]‘my_mc’[/COLOR][COLOR=#000000]][/COLOR][COLOR=#000000])[/COLOR];
[COLOR=#808080]*// generates a syntax error *[/COLOR]

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eg2 would probably work (bit hacky) if I knew how to destroy a string

 ActionScript Code:
 [FONT=Courier New][LEFT]sub = [COLOR=#000000]{[/COLOR][COLOR=#000000]};[/COLOR]

sub +=[COLOR=#ff0000]“menu1:{url:[‘this.swf’], targ:[‘my_mc’]”[/COLOR];
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Any ideas or links to tuts? im a little stumped :rocker: