兼容linux firefox和windows ie的xml处理代码

function   XmlDom(){
    if(window.ActiveXObject){
        var   arrSignatures=new   Array(5);
arrSignatures[0]= "MSXML2.DOMDocument.5.0 ";
arrSignatures[1]= "MSXML2.DOMDocument.4.0 ";
arrSignatures[2]= "MSXML2.DOMDocument.3.0 ";
arrSignatures[3]= "MSXML2.DOMDocument ";
arrSignatures[4]= "Microsoft.XmlDom ";
        for(var   x=0;x <arrSignatures.length;x++){
            try{   return   new   ActiveXObject(arrSignatures[x]);}
    catch(oError){/*ignore*/}
        }
        throw   new   Error( "MSXML   is   not   installed   on   your   system. ");
    }
    else   if(document.implementation   &&  document.implementation.createDocument)   return  document.implementation.createDocument( " ", " ",null);
    else   throw   new   Error( "Your   browser   doesn 't   support   an   XML   DOM   object. ");
}