Recently I integrated my web app with Azure ACS but was having a difficult time signing out of ACS (deleting my cookie off the .accesscontrol.windows.net server). The following code will create a wsignout1.0 message. Essentially it will construct a url with the action parameter set to “wsignout1.0”. An additional parameter “wreply” allows you to specify a url to redirect to after you have been signed out:

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