bootstrap modal - how to set the modal width only as wide as the text it displays

Question

I am using Bootstrap Responsive v2.3.2 modal to display a pop up modal to users.

How do I resize the modal so that the modal is only as wide as the message it displays and not a fixed with or greater than the width on the users screen and with the modal still centered in the users screen?

I have tried to add the width: auto; in the css as follows:

.modal {
    position: fixed;
    top: 3%;
    right: 3%;
    left: 3%;
    width: auto;
    margin: 0 auto; /* this line of code will center align the modal to the screen */
    background-color: orange;
}

.modal-body {
    height: 60%;
    max-height: 350px;
    padding: 15px;
    overflow-x: hidden;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    margin-left: 0;
    background-color: yellow;
    width: auto;
}

.modal-confirm-max-width {
    min-width: 50px;
    max-width: 950px;
    word-wrap: break-word;
    word-break: break-word;
    margin: 0 auto; /* this line of code will center align the modal to the screen */
    width: auto;
    background-color: lime;
}