This question is related to this question. The answer shows very nice way to extrude polygons that have holes (see the excellent live example). The main learning of the answ
You can merge geometries as in the following snippet, resulting in just a single mesh. From your prior questions, you already know how to texture a single geometry.
var geometry1 = new THREE.ExtrudeGeometry( shape1, extrusionSettings );
var geometry2 = new THREE.ExtrudeGeometry( shape2, extrusionSettings );
geometry1.merge( geometry2 );
. . .
var mesh = new THREE.Mesh( geometry1, material );
scene.add( mesh );
Fiddle: http://jsfiddle.net/pHn2B/88/
Fiddle: http://jsfiddle.net/C5dga/13/ (with texture)
EDIT: As an alternative to creating separate geometries and using the merge utility, you can create a single geometry using the following pattern, instead:
var geometry1 = new THREE.ExtrudeGeometry( [ shape1, shape2 ], extrusionSettings );
EDIT: updated to three.js r.70