Feature summary (what you would like to be able to do and where):
I would like a way to be able to set preloadparams[] equal to the inputted text itself when using the InputBox extension.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
I'd like to get the input form at WP:UNDELETE to automatically include the name of the page you're trying to undelete in the preload rather than just "1=Page name goes here". This feature would be useful in many other places with a similar issue, such as the Teahouse, DYK,

Benefits (why should this be implemented?):
Would allow us to make input boxes work better for users