Dialog Button Text Problem

Hi all

I am probably missing something simple here, I am using jQuery Dialog and I am trying to pass the Button text to the dialog function in the following manner:

<script type="text/javascript">
    function showDialog($url, $title, $form_id, $buttontext) 
	{
        $('<div>').dialog({
            modal: true,
            open: function ()
            {
                $(this).load($url);
            },         
            height: 500,
            width: 700,
            title: $title,
            buttons: {
                $buttontext: function() {
                    $($form_id).submit();
                    $( this ).dialog( "close" );
                },
                Cancel: function() {
                    $( this ).dialog( "close" );
                }	
			}
        });
		
	
	};

</script>

And I am passing the following:

<a href="#" onclick="showDialog('templates/dialogs/dialog.editcheckpoint.php', 'Edit Checkpoint', '#editcheckpoint', 'Update Checkpoint');\\">Edit</a>

This works all apart from the button text which remains as $buttontext where it should be ‘Update Checkpoint’

I am sure I am missing something obvious or doing something stupid! I use the same Dialog function for a number of different tasks in the interface so want to customize the button text as I do with the title etc.

Thanks for any help

Matt

For anyone else trying to do this I have managed it with this method:

    function showDialog($url, $title, $form_id, $buttontext, $cancel)
	{
		var buttons = {};
		buttons[$buttontext] = function() { $($form_id).submit(); $( this ).dialog( "close" ); }
		buttons[$cancel] = function() {  $( this ).dialog( "close" ); }

        $('<div>').dialog({
							modal: true,
							open: function ()
							{
								$(this).load($url);
							},
							height: 500,
							width: 700,
							title: $title,
							buttons :buttons
       					 });
		
	};

hey good tricks ii have go through with this and find its a good trick.Thanks!!!