create WI custom field dependencies

I customized and added 2 work item fields i.e. (version# and release#) and both are dropdownlists.
I was wondering is there a way in TFS that i could make release# dependent on version#.
So, if i choose "ABC1221" from version# drop downlist, then release# dropdownlist should only show releases for that version only i.e. "ABC1221.2.5","ABC1221.2.6","ABC1221.2.7".
if i choose "xyz3553" from version# drop downlist, then release# dropdownlist should only show releases for that version only i.e. "xyz3553.2.5.7","xyz3553.2.5.8","xyz3553.2.5.9".

Any thoughts

Visual Studio Team System42

You can use WHEN rules in workitemtype xml, for example,

<FIELD refname="A"> <WHEN field="B" value="1"> <ALLOWEDVALUES ...

Download VS SDK from http://msdn.microsoft.com/vstudio/extend and check out the documents & samples under "VisualStudioTeamSystemIntegration\Work Item Tracking" on "Authoring Work Item Types.doc" that explains the rules in detail.

MSDN topic http://msdn2.microsoft.com/en-us/library/ms243849.aspx also has info on this.