lib/Ext/MessageBox.js
function(title, message, fn, scope, multiLine, value, prompt) {
        return this.show({
            title    : title || null,
            message  : message || null,
            buttons  : Ext.MessageBox.OKCANCEL,
            scope    : scope,
            prompt   : prompt || true,
            multiLine: multiLine,
            value    : value,
            fn: function() {
                if (fn) {
                    fn.apply(scope, arguments);
                }
            }
        });
    }
function(title, message, fn, scope, multiLine, value, prompt) {
        return this.show({
            title    : title || null,
            message  : message || null,
            buttons  : Ext.MessageBox.OKCANCEL,
            scope    : scope,
            prompt   : prompt || true,
            multiLine: multiLine,
            value    : value,
            fn: function() {
                if (fn) {
                    fn.apply(scope, arguments);
                }
            }
        });
    }
Displays a message box with OK and Cancel buttons prompting the user to enter some text (comparable to
JavaScript's prompt). The prompt can be a single-line or multi-line textbox. If a callback function is passed it
will be called after the user clicks either button, and the id of the button that was clicked (could also be the
top-right close button) and the text that was entered will be passed as the two parameters to the callback.

Example usage:

@example
Ext.Msg.prompt(
'Welcome!',
'What\'s your name going to be today?',
function (buttonId, value) {
console.log(value);
},
null,
false,
null,
{
autoCapitalize: true,
placeHolder: 'First-name please...'
}
);

@param {String} title The title bar text.
@param {String} message The message box body text.
@param {Function} fn A callback function which is called when the dialog is dismissed by clicking on the configured buttons.
@param {String} fn.buttonId The `itemId` of the button pressed, one of: 'ok', 'yes', 'no', 'cancel'.
@param {String} fn.value Value of the input field if either `prompt` or `multiLine` option is `true`.
@param {Object} fn.opt The config object passed to show.
@param {Object} scope The scope (`this` reference) in which the callback is executed.

Defaults to: the browser window.

@param {Boolean/Number} [multiLine=false] `true` to create a multiline textbox using the `defaultTextHeight` property,
or the height in pixels to create the textbox.

@param {String} [value] Default value of the text input element.

@param {Object} [prompt=true]
The configuration for the prompt. See the {@link Ext.MessageBox#cfg-prompt prompt} documentation in {@link Ext.MessageBox}
for more information.

@return {Ext.MessageBox} this