Javascript issue with submitForm

My form has a button with a javascript associated to the Mouse Up event.

The script code follows:

if (FormOk()==true) {

    //Confirmation request

    var nButton = app.alert({

      cMsg: "Do you want to submit this application form?",

      cTitle: "Submit form", nIcon: 2, nType: 2});

    if ( nButton == 4 ) {

        //Form collection email address

        cToAddr = "mailbox@example.com";

        // Set the subject and body text for the email message

        var cSubLine = "Application for Employment";

        // Set the subject and body text for the email message

        var cBody = "Instructions to handle this application form:\n" +

          "1. Double-click the attachment\n" +

          "2. Select a response file";

        //Build email URI

        var cURI = encodeURI("mailto:" + cToAddr + "?" +

          "subject="+ cSubLine + "&body=" + cBody);

        //Exception handling

        try {

            //Submit form by email

            this.submitForm({cURL: cURI, cSubmitAs: "PDF"});

            app.alert({

              cMsg: "Your application has been submitted",

              cTitle: "Submit form", nIcon: 3});

        } catch(e) {

            //Display error info

            app.alert({

              cMsg: "Application NOT submitted\n\n" +

                e.name + " on line: " + e.lineNumber +

                "\n\n" + cURI});

        }

    } else {

          app.alert({

            cMsg: "Your application WAS NOT submitted",

            cTitle: "Submit form", nIcon: 3});

    }

}

This should work as per the documentation but it is not and it is driving me crazy.

The issue happens using my Outlook mail client and also using Gmail webmail client.

I would appreciate any ideas about how to solve this issue.

Thanks in advance!