Want to run javascript code

Subject: I would like to run a javascript code
I want to take data of that input box into my “var jt1” variable but both are in different pages that’s why not getting that “input box” name in “Insert dynamic data field” so the query is that how can I get this input box value in my variable.
for example==
var jt1=InputjobTitlevalue’s

Have you figured out how to do this?