How to see if an ip helper-address is configured on a VLAN

Question

Hi - I'm not exactly new to networking but this question will likely say otherwise :)
I'm trying to figure out the command to show the running-config of a VLAN.  The goal is to see if an ip helper-address has been configured on a VLAN.
This is both for a Cisco 6509 and Nexus 5k.
I simply don't know all the commands for VLANs so I can't get this info presented to me.
Thank You in advance

Answer 1

Thanks for the prompt reply!  Still no bueno though.
On the 6509 I get the following:
6509#show ip interface vlan xxx
                                           ^
% Invalid input detected at '^' marker.
On the Nexus 5K I can't complete the command, stops down at show ip interface with the following listed as ? after interface:
5K# show ip interface ?
  <CR>
  >                    Redirect it to a file
  >>                  Redirect it to a file in append mode
  A.B.C.D       Display interface for local IP address
  brief              Display summary of IP interface status and configuration
  ethernet        Ethernet IEEE 802.3z
  loopback      Loopback interface
  mgmt            Management interface
  operational   Display only interfaces that are administratively enabled
  port-channel  Port Channel interface
  vrf                   Display per-VRF information
  |                      Pipe command output to filter