Jquery :: Manipulate The Dynamic Textboxes?

i'm trying to manipulate dynamic textboxes using jquery such that when the value of the textbox_1 is, say, 'abcd' a new text box textbox_2 would be introduced and when the value of textbox_2 is again 'abcd' a third one is introduced and so on. ive managed to do this with the following code, but with a little problem.

$(document).ready(function(){
var cnt = 1;
$("#inpu_"+cnt).keyup(function () {

[code]...

the problem is that although textbox_2 is displayed instantaneously, the 3rd and 4th does not when the value of textbox_2 is 'abcd'. but they are displayed as soon as a key is pressed in the original textbox (textbox_1). that is the 3rd one is displayed when textbox_2's value is 'abcd' and a key is pressed while inside textbox_1. and so on. [edit 1] btw, inside body tag ive created a div and given the id content. and inside it is the textbox_1 with the id 'inpu_1'. the original one that is.