Generate XML data file on Click Button

Dear All,

I have create one sample PDF with 2 fields(Name, City) using adobe live cycle designer.

While clik on Submit i need to save the XML file on my machine of inputed data.(Ask where to save .xml file)

I have written code onclick event of button :  xfa.host.exportData("",0);

I didn't get any output file from this, Can any one suggest me how can i get the XML file with data?

Thanks and regards,

Jaydeep