Want to change presence från visable screen only to visable pring only or visible when event happens in livecycle

Help why wont it work?

Background:

I want a digital signaturefield not to show when printing at first. But want a button to change that so a copy can be printed.

presence is default visible (screen only) on field.

Then when button is clicked I want it to be just Visible

but this doesnt seem to work. the print function does however work.

form1.Sid1.Button1::click - (JavaScript, client)

X.presence = "visible";
print.execEvent("click");

best regards
Leif