how to make a part of the textbox as readonly

Question

i have a tagtextbox on my page when a user selects a category that category name goes to tagtextbox

now i want that this category name user cant change but he can append some more tags means first tag becomes readonly and further he can add too in same text box

Answer 1

You can't make part of a textbox editable and another not.

My suggestion would be to change the type of element from a TextBox to a div or span via Javascript as soon as the user begins to enter the next tag.

Answer 2

If you want to allow append has in "paste" action, then you can't do that. Else and you just want to append via your code, why not use just a div to show what he has selected and add the selections to your post on a hidden textbox?

Answer 3

This is not possible.

Instead, you can put the first category name in a <span>, and put the textbox after the span.
You can then apply border: none to the textbox and make your own border around the entire thing to make it look like a single textbox.