How can I restyle a submit button?

Answer 1

Use an <input type="image" ... /> tag:

<input type="image" src="/path/to/image.file" alt="Alt text" />

It acts as a submit button, but displays an image instead.

Answer 2

use css.

.as_link {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0px;
    color: red;
    float: right;
    etc...
}

Etc.

Edit: just re-read your question. Use the above but call it "x", I'm not sure that you're going to be using this for a web .net app (as I'm not familliar with the way of .net but if you are it will work, else ignore me :) )