Undefined when getting a value through global variable

var f2 = Ti.UI.createTextField({
        value: myproperties.f2,
});
 
 Titanium.App.Properties.setString("f2",f2.value);
     myproperties.f2 = Titanium.App.Properties.getString("f2");
 
    f2.addEventListener('focus',function(e){
        alert(myproperties.f2);
 
    });

Hi, I am getting undefined value after I have entered a value in the text field. I should get the value which I have entered previously, but here Iam getting as "undefined" in the textfield. Thanks