Finding export options 3D Version 6

[Metro Golden]

Sorry, I keep knocking my head on finding the ability to export a png or gif with transparency. I understand there is an export dialogue box where I can select transparency, but I can't find it! When I select export, I go to a more or less vanilla window showing where I can save and what file type but without options. Can anyone tell me why? Thanks.

[steve.ledger]

The options box appears after selecting the file type.
Choose PNG for example, give the file a name then click 'Save' - the Export options will then appear allowing you to choose transparent type (and more).

[Metro Golden]

How did I not see that! Thanks Sledger!