Custom tag button code

Hi,

I recently came across the following code which I have adjusted to meet my needs, but I am not sure whether the code is correct and also how to install it?

I have read the documentation about installing and adding buttons but I do not quiet understand the button bit. Because it mentions something about adding a myconfig.js does that mean I will no longer be able to see the buttons contained in the fckconfig.js file?

I am quiet confused attached is my plugin code;

/***
 * Create blank command
 */
var FCKPixelCaps_command = function()
{

}

/***
 * Add Execute prototype
 */
FCKPixelCaps_command.prototype.Execute = function()
{
        // get whatever is selected in the FCKeditor window
        var selection = FCK.EditorDocument.getSelection();

        // if there is a selection, add tags around it
        if(selection.length > 0)
        {
                FCK.InsertHtml('<span class="nolink">' + selection + '</span>');
        } else {
                        // for debugging reasons, I added this alert so I see if nothing is selected
                alert('nothing selected');
        }
}

/***
 * Add GetState prototype
 * - This is one of the lines I can't explain
 */
FCKPixelCaps_command.prototype.GetState = function()
{
        return;
}

// register the command so it can be use by a button later
FCKCommands.RegisterCommand( 'PixelCaps_command' , new FCKPixelCaps_command() ) ;

/***
 * Create the  toolbar button.
 */

// create a button with the label "nolink" that calls the nolink_command
var oPixelCaps = new FCKToolbarButton( 'PixelCaps_command', 'Pixels & Pulp Caps' ) ;
nolink.IconPath = FCKConfig.PluginsPath + 'nolink/nolink.jpeg' ;

// register the item so it can added to a toolbar
FCKToolbarItems.RegisterItem( 'PixelCaps', oPixelCaps ) ;

Some help would be greatly appreciated.....