APEX

i have a button whose action when clicked is set to redirect to URL and in target i have written

  javascript: $('#dept').hide();   // it works fine and hides a region
   javascript: $('#saveTA').hide();  //does not hide the button

  NOTE: the button saveTA and the one i m clicking to hide it are in different regions. can tat be a matter?

  

where saveTA is the static id of the button that i want to hide. using this technique, i can hide relevant regions but same function and technique isnt working to hide a button.

help is drastically requested.