Codeigniter - Autocomplete with Jquery (small article)

[eluser]Unknown[/eluser]
It´s all Ok

but how can i passing parameters to the controller from a input text?

I try whith this:

$("#direccion").autocomplete(
"<?php echo base_url();?>index.php/ajax/direcciones/"+$("#cp").val()+"/", {
width: 260,
selectFirst: false
});


But $("#cp").val() not pass !!!

What´s wrong? Thanks for all