When you add a 'Cancel' button to your page, you can re-direct to the current page (I beleive)...
<xp:button value="Cancel" id="button1">
<xp:eventHandler event="onclick" submit="true" immediate="true" save="false">
<xp:this.action>
<xp:openPage name="YourXPage"></xp:openPage>
</xp:this.action>
</xp:eventHandler>
</xp:button>
I think the important piece there is the the "immediate" parameter set to "true".
I believe this causes the inputted values to be discarded.