Doing ecmascripting with Desiger and my road suddenly stopped at this

parser = new DOMParser();
Because I got this

Error Evaluating Script com.novell.soa.script.mozilla.javascript.EcmaError: ReferenceError: "DOMParser" is not defined. (unnamed script#50)
Should DOMParser be included in IDM? If not is there any other way to parse my XML than to add children one by one? Hate to invent wheel again.. or was is rectangle?