Hello,
I have downloaded the CKEditor 4.x and i was trying to create a custom toolbar, i make it in the config.js, but i don't arrived to created it. I have read the Doc and i have used the example.
CKEDITOR.editorConfig = function (config) {
config.toolbar = [
{ name: 'document', items: ['Source', '-', 'NewPage', 'Preview', '-', 'Templates'] },
{ name: 'clipboard', items: ['Cut', 'Copy', 'Paste', 'PasteText', 'PasteFromWord', '-', 'Undo', 'Redo', 'iFrame'] },] },
'/',
{ name: 'basicstyles', items: ['Bold', 'Italic'] }
];
};

If you use the latest version
If you use the latest version of CKEditor, there is a slight changes with the code in config.js. Based from your code that should be:
CKEDITOR.editorConfig = function (config) { config.toolbar = [ { name: 'document', groups: [ 'mode', 'document', 'doctools' ], items: [ 'Source', '-', 'NewPage', 'Preview', '-', 'Templates' ] }, { name: 'clipboard', groups: [ 'clipboard', 'undo' ], items: [ 'Cut', 'Copy', 'Paste', 'PasteText', 'PasteFromWord', '-', 'Undo', 'Redo' ] }, { name: 'insert', items: [ 'Iframe' ] }, '/', { name: 'basicstyles', groups: [ 'basicstyles' ], items: [ 'Bold', 'Italic' ] } ]; };