Adobe Rader, Javascript, MouseEvent

/*
https://opensource.adobe.com/dc-acrobat-sdk-docs/acrobatsdk/html2015/index.html?rhtocid=_6_1_8_23_1_1#t=Acro12_MasterBook%2FJS_API_AcroJS%2FField_methods.htm%23XREF_37472_setAction
*/
app.addMenuItem({
    cParent: "SignMenu",
    cName: "mouse",
    cUser: "mouse",
    cExec: "Mouse()",
});
var Mouse = app.trustedFunction( function ()
{
    app.beginPriv();
    console.show();
    doIt( dialog, this );
    app.endPriv();
});
function doIt(dialog,doc)
{
    dialog.doc = doc;
    console.println(doc);
    doc.addField("z","text",0,this.getPageBox());
  z = this.getField("z");
  z.borderColor = color.green;
  //z.set
  doc.addField("a","text",0,[10,10,150,150]);
    doc.addField("b","text",0,[250,250,400,400]);
    a = this.getField("a");
    a.setAction( "MouseEnter", "nP()" );
    a.setAction( "MouseExit", "nP()" );
    a.setAction( "MouseUp", "rField()" );
    a.borderColor = color.red;
    a.lineWidth = 1;
  a.fillColor = color.yellow;
    b = this.getField("b");
    b.value = event.value;
    b.borderColor = color.blue;
    b.lineWidth = 3;
    //nP(doc);
    //rField();
}

nP = app.trustedFunction ( function(doc)
{
    app.beginPriv();
    console.println(event.source +" "+event.target);
    console.println(this.getField("a"));
    this.borderWidth=5;
    app.endPriv();
});

rField = app.trustedFunction ( function(doc)
{
    app.beginPriv();
  console.println("_"+this+"_");
    //this.removeField("b");
    app.endPriv();
});


myTrustedGetGlobal = app.trustedFunction ( function()
{
    app.beginPriv();
    var y = global.x;
    return y
    app.endPriv();
});
myTrustedSetGlobal = app.trustedFunction ( function(value)
{
    app.beginPriv();
    global.x=value;
    app.endPriv();
});