Something

<xar:set name="xarVarFetch('textfield',    'str',   $rname,     NULL, XARVAR_NOT_REQUIRED))</xar:set>
<xar:if condition="!empty($rname)">
    <xar:set name="foo">xarUserSetVar('rname',$rname)</xar:set>
<xar:else />
    <form name="profile_form" method="post" action="#xarservergetcurrenturl()#">
    <xar:set name="$reaname">xarusergetvar('rname')</xar:set>
    <input name="textfield" type="text" value="#$reaname#" size="32">
    <input type="submit" value="Update">
</form> 
</xar:if>