I am following the example here about gird-fields. My question is why is there a button on create on each of the columns? How would I get rid of it and have sortable columns instead?

http://doc.silverstripe.org/framework/en/reference/grid-field

This is the code from the example page. When displayed each column has a button above it that links to a non-existent page. How do I get rid of the buttons?

public function AllPages() {
    $gridField = new GridField('pages', 'All pages', SiteTree::get()); 
    $dataColumns = $gridField->getConfig()->getComponentByType('GridFieldDataColumns');
    $dataColumns->setDisplayFields(array(
        'Title' => 'Title',
        'URLSegment'=> 'URL',
        'LastEdited' => 'Changed'
    ));
    return new Form($this, "AllPages", new FieldList($gridField), new FieldList());
}

You can manipulate the GridField through the GridFieldConfig system. http://doc.silverstripe.org/framework/en/reference/grid-field#configuration has an overview of how it works. To add sortable, you'll need a module like https://github.com/ajshort/silverstripe-gridfieldextensions which adds sortable rows.