When user hits checkbox enter text in text box

I have developed a form all working fine but am struggling on the following.

I need a checkbox for an item, when the checkbox is true the user can enter text in a text box, only if the checkbox is ticked.

I have numerous items I need for this.

Hope someone can help. Thanks

 

What you are after is more javascript than PHP. Here's an example/tutorial for doing this with a drop down, same basic principle applies for a text input.

http://codecooking.blogspot.com/2006/02/toggle-button_16.html

Here's another but the demo page is missing :

http://www.annedorko.com/blog/toggle-enable-and-disable-a-form-field-with-a-checkbox-javascript-101

 

Thanks shallowink. Thanks to your information have now got it working. Thanks