How do I increment a NumericField value on a newly created sheet?

I'm fairly new to javascript so please forgive me if this is considered basic.  I have made a button in LiveCycle Designer that duplicates the current page which contains a Numeric Field called "Image1Text".  I want to increment the field value on the newly created page.  I've tried many different things but all I can get it to do is increment the value on the original page instead.  Any suggestions?

Code for my button:

parent.instanceManager.addInstance(parent.index);

xfa.host.pageDown();

this.Image1Text.rawValue = parseInt(Image1Text.rawValue) + 1;