jquery - Google Custom Search GCSE "Input Box Value"? -

how value of gcse inputbox? id is:

<input id="gsc-i-id2" .... 

but can not value of using:

$(document).ready(function() {     alert( $( 'input#gsc-i-id2' ).val() ); }) 

it not working. why please?

note ** in page source, whole google cse section not visible :s
how catch box please?