Bug fix: don't assume that the hierachical key is called 'parent_id'

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@1456 a333f486-631f-4898-b8df-5754b55c2be0

application/ui.extkeywidget.class.inc.php

@@ -392,7 +392,8 @@ EOF
 			$oSet = new DBObjectSet($oFilter);
 		}
 
-		$this->DumpTree($oPage, $oSet, 'parent_id', $currValue);
+		$sHKAttCode = MetaModel::IsHierarchicalClass($this->sTargetClass);
+		$this->DumpTree($oPage, $oSet, $sHKAttCode, $currValue);
 
 		$oPage->add('</td></tr></table>');
 		$oPage->add('</div>');