Silverlight Button "isWindowless" setting dynamically -

i generating silverlight button through following code.

    silverlight.createobjectex(     {         source: controlsource,          parentelement: container,         id: "controlid",         properties: { width: w, height: h, version: "4.0", background: nusa_recordbuttonbackgroundcolor, enablehtmlaccess: "true", initparams: params},         events: { onload: oncontrolload }                 } 

here problem is, when popup placed on silverlight button, button ovveriding popup. here z-index not working properly. "iswindowless" property has set true, make functionality work properly.

now, above code in js file has reference location, not our server.i using reference of js file in page. in above method have add 1 more property [iswindowless ='true']

can tell , how add property existing method in js file, through javascript in current page (or) how ovveride existing method through javascript

so cannot change method in .js file? here method (not written me) refreshes silverlight plugin same values, , set windowless property. may starting point you...

function refreshsilverlight() {     var source;     var initparams;     var slcontrol = window.document.getelementbyid('webresource_kbarticlelookup');     var parent = slcontrol.parentnode;      (var = 0; < slcontrol.childnodes.length; i++)     {        (var j = 0; j < slcontrol.childnodes.item(i).attributes.length; j++)         {           if (slcontrol.childnodes.item(i).attributes.item(j).nodevalue == 'source')            {               (var k = 0; k < slcontrol.childnodes.item(i).attributes.length; k++)               {                  if (slcontrol.childnodes.item(i).attributes.item(k).nodename == 'value')                  {                      source = slcontrol.childnodes.item(i).attributes.item(k).nodevalue;                  }               }           }           if (slcontrol.childnodes.item(i).attributes.item(j).nodevalue == 'initparams')           {             (var k = 0; k < slcontrol.childnodes.item(i).attributes.length; k++)              {                if (slcontrol.childnodes.item(i).attributes.item(k).nodename == 'value')                {                   initparams = slcontrol.childnodes.item(i).attributes.item(k).nodevalue;                }             }          }       }     }      parent.removechild(slcontrol);     silverlight.createobject(source,                              parent,                              "webresource_kbarticlelookup",                              {                                  width: '800',                                  height: '600',                                  windowless: 'true',                                  enablehtmlaccess: 'true',                                  minruntimeversion: '4.0'                              },                              null, initparams, null); 

}