The layerdefs parameter needs to contain the layer ID to which you are applying your definition query:[INDENT]&layerdefs=5:STATE_FIPS%3D'20'
[/INDENT]To apply definition queries to more than one layer, separate with semicolons:[INDENT]&layerdefs=5:STATE_FIPS%3D'20';3:STATE_FIPS%3D'20'[/INDENT]