Download pdf in mobilegap in ios

i want to download a pdf file created in mobilegap in ios.but it is not working. when i click the download card button,it opens a pdf file but it is not downloading. i tried every possible code,but its not working.when i click the button,it opens the pdf but either the home button stops working or its not downloading.it is created in javascript

$(document).on('pageshow', '#downloadidcard', function(){

       var b = new FileManager();
    new FileManager().download_file('http://ift.tt/1DahtId','_blank',Log('downloaded success'));

            var mobileNumber=localStorage.getItem("MOBILENO");
            var memID=localStorage.getItem("MEMBERID");
            //console.log("IDCARD URL.............http://ift.tt/1ETvvmi"+memID+"&mobileNo="+mobileNumber);
            //window.plugins.fileOpener.open("http://ift.tt/1ETvvmi"+memID+"&mobileNo="+mobileNumber);
            //window.plugins.fileOpener.open("http://ift.tt/1DahtId"+memID);

               start_examples();/*
                    $.ajax({
                        context: this,
                        dataType : "html",
                        url : "http://ift.tt/1DahtId"+memID,
                        beforeSend: function() {
                                    $.mobile.loadingMessageTextVisible = true;
                                    $.mobile.loadingMessage = "please wait...";
                                    //$.mobile.showPageLoadingMsg();
                                    $.mobile.loading('show')
                        },
                        success : function(results) {
                            $('#contentview').html(results);
                            $.mobile.hidePageLoadingMsg();
                        },error: function (request, status, error) {
                                    console.log(error+'............Request IDCARD Error...'+status+'.....'+request.responseText);
                                    $.mobile.hidePageLoadingMsg();
                                alert('Network error please try later');
                            }
                    });*/
    });