Textbox number counter. Help

hello,
I have a textbox in my .net page, and totally new to java script.

How do i get a script that will count the data being written in the text box to show increments of 100 and write the value to the bottom of the textbox.

e.g. When u get to 100, at the bottom it says “1st hundred”

… and to 200 it writes “2nd hundred”

UP to 500 ???

Please help
thanks

Q1: Do you mean textbox, or textarea?
Q2: Can you give an example of what might be written to the box? Is it a very long string of text or numbers?
Q3: Do you want the total to be changing as the information is being typed in?

If your input field:
<form id=“yourform” name=“yourform”>
<input name=“yourfield” id=“yourfield” />

I think you can check the length of your input field like this:
document.yourform.yourfield.value.length

More here: