diff -u -r1.1 -r1.2
--- compact.xml	22 May 2008 07:27:27 -0000	1.1
+++ compact.xml	3 Jul 2008 23:27:19 -0000	1.2
@@ -41,27 +41,27 @@

 	  <position z="2.692"/>
 	</module_component>
       </module>

-      <layer module="SiTrackerModule">

+      <layer module="SiTrackerModule" id="1">

 	<barrel_envelope inner_r="195.0" outer_r="245.0" z_length="267.0 * 2.0"/>
 	<rphi_layout phi_tilt="0.19" nphi="16" phi0="0.196" rc="205.0" dr="0"/>
 	<z_layout dr="5.5" z0="218.0" nz="7"/>
       </layer>

-      <layer module="SiTrackerModule">

+      <layer module="SiTrackerModule" id="2">

 	<barrel_envelope inner_r="451.0" outer_r="501.0" z_length="608.0 * 2.0"/>
 	<rphi_layout phi_tilt="0.19" nphi="36" phi0="0.087" rc="461.0" dr="0.0"/>
 	<z_layout dr="5.5" z0="559.0" nz="15"/>
       </layer>

-      <layer module="SiTrackerModule">

+      <layer module="SiTrackerModule" id="3">

 	<barrel_envelope inner_r="706.0" outer_r="756.0" z_length="948.0 * 2.0"/>
 	<rphi_layout phi_tilt="0.19" nphi="54" phi0="0.058" rc="716.0" dr="0.0"/>
 	<z_layout dr="5.5" z0="899.0" nz="23"/>
       </layer>

-      <layer module="SiTrackerModule">

+      <layer module="SiTrackerModule" id="4">

 	<barrel_envelope inner_r="962.0" outer_r="1012.0" z_length="1289.0 * 2.0"/>
 	<rphi_layout phi_tilt="0.19" nphi="72" phi0="0.0436" rc="972.0" dr="0.0"/>
 	<z_layout dr="5.5" z0="1240.0" nz="29"/>
       </layer>

-      <layer module="SiTrackerModule">

+      <layer module="SiTrackerModule" id="5">

 	<barrel_envelope inner_r="1218.0" outer_r="1265.0" z_length="3260.0"/>
 	<rphi_layout phi_tilt="0.19" nphi="90" phi0="0.01745" rc="1228.0" dr="0.0"/>
 	<z_layout dr="5.5" z0="1581.0" nz="37"/>