The following SCXML strategy shows how to delete a property from the user data of an interaction.
<scxml version="1.0" xmlns="http://www.w3.org/2005/07/scxml"
xmlns:queue="www.genesyslab.com/modules/queue"
xmlns:dialog="www.genesyslab.com/modules/dialog"
initial="initial">
<state id="initial">
<transition event="interaction.added" target="setudata"/>
</state>
<state id="setudata">
<onentry>
<script>
var data = new Object();
data.details = new Object();
data.details.name = "Smith, John";
data.details.age = 45;
_genesys.ixn.setuData(data);
</script>
</onentry>
<transition event="interaction.udata.changed"
cond="_genesys.ixn.interactions[0].udata.details.name=='Smith, John'
&&
_genesys.ixn.interactions[0].udata.details.age==45"
target="check"/>
</state>
<state id="check">
<onentry>
<script>
_genesys.ixn.deleteuData("details.age");
</script>
</onentry>
<transition
event="interaction.udata.changed"
cond="_genesys.ixn.interactions[0].udata.details.name=='Smith, John'
&&
_genesys.ixn.interactions[0].udata.details.age==undefined"
target="routing"/>
</state>
<state id="routing">
<onentry>
<queue:submit priority="5" timeout="20">
<queue:targets type="dn">
<queue:target name="'7102'"/>
</queue:targets>
</queue:submit>
</onentry>
<transition event="queue.submit.done" target="exit">
<log expr="'DONE'"/>
<log expr="_event.data.targetselected"/>
</transition>
<transition event="error.queue.submit" target="error"/>
</state>
<final id="exit"/>
<final id="error"/>
</scxml>