I have this code:

```
$('.b-icon.b-icon_del').click(function(e) {
showConfirmDialog('Are you sure you want to delete this document?',deleteDocument(window.lastSelectedRowId), 'Delete document');                    
}); 

function showConfirmDialog(content, callback, pTitle, obj){
    return showDialogEx(content, callback, pTitle, obj, "Yes", "No");
}

function showDialogEx(content, callback, pTitle, obj, okButtonLabel, cancelButtonLabel){
    var str = "#_showMessageDialog";
    var showMessageDialog = $(str);
    if(showMessageDialog.length == 0){
        $('body').append('<div id="_showMessageDialog"></div>');
        showMessageDialog = $(str);
    }
    showMessageDialog.val("");
    showMessageDialog.append('<p id="_showMessageDialogContent">'.concat(content, '</p>'));

    var my_buttons = {};
    my_buttons[cancelButtonLabel] = function(){
        $(this).dialog("close");
        $(this).html("");
        $(this).dialog("destroy");
    };
    my_buttons[okButtonLabel] = function(){
        callback();
        $(this).html("");
        $(this).dialog("close");
        if(obj){
            obj.focus();
        }
        $(this).dialog("destroy");
    };

    showMessageDialog.dialog({
        modal : true,
        resizable : true,
        title : pTitle,
        minWidth : 250,
        width : 450,
        buttons : my_buttons
    });

}

```

And then I click on button with classes `.b-icon.b-icon_del` it seems like executing both `deleteDocument(window.lastSelectedRowId)` and `showConfirmDialog('Are you sure you want to delete this document?',deleteDocument(window.lastSelectedRowId), 'Delete document');` at the moment. I just want that callback function (which is `deleteDocument(window.lastSelectedRowId)`) invoke after user clicks "OK" button. Thanks!