You can't do it using standard declarative methods.

Pretty much all you can do with dependant fields you find here https://help.salesforce.com/HTViewHelpDoc?id=fields_defining_field_dependencies.htm&language=en_US

So either you have to start using visualforce or you see the fields permanently.

You can't do it using standard declarative methods.

Pretty much all you can do with dependant fields you find here https://help.salesforce.com/HTViewHelpDoc?id=fields_defining_field_dependencies.htm&language=en_US

So either you have to start using a visualforce override or you'll see the fields permanently.