PDF Export AS FDF Javascript

Hello, 

I need to export my pdf as fdf and save it server. I have script that is working, but it's not working in adobe acrobat reader. Can someone please help me know I can export in Reader. 

var fields = [];
var Arrays =[];

app.alert("Started")
for (var i = 0; i <= this.numFields - 1; i++)
{
fields.push(this.getNthFieldName(i));
Arrays = fields.sort( function(a,b)
{return a - b; } );
}

//Don't change JavaScript, expecet Domain name, otherwise It will not work
var aSubmitFields = fields ;
var cFDF = this.exportAsFDF({
aFields:aSubmitFields,
//cPath: "JHHJH.fdf",
//bAnnotations:true,
});