Match content in HTTP request and response - and block if value does not match

Managed to resolve myself - Just to advise found I needed to switch

when HTTP_RESPONSE_DATA {
        if { [string match  $orgstring [HTTP::payload]] } {
        log local0. "Temp fix-irule matched OrgString - allowing response)      
        return
        }{
        else discard
        log local0. "Temp fix-irule failed to match OrgString - dropping response"
    }
    }
`

To be :

`  if response data contains match allow request - else block response     
when HTTP_RESPONSE_DATA {
            if { [HTTP::payload] contains $orgstring  } {
        HTTP::release
                log local0. "Temp fix-irule match HomeOrg $homeorg to EnterpriseOrg $orgstring allowing request"
        }
        else {
                HTTP::respond 500 content BLOCKED
                log local0. "Temp fix-irule HomeOrg $homeorg to EnterpriseOrg $orgstring does not match -- dropping request"
    }
    }