Tinymce dialog's textbox overlaps with label

Question

As the title suggests, Tinymce's dialog box's textbox is overlapping with the label.

ed.addButton('addref', {
                title : 'Add References',

                image : 'img/example.gif',
                onclick : function() {
                    ed.windowManager.open({
                        title: 'Add References',
                        body: [
                            {type: 'textbox', name: 'refName', label: 'Name'},
                            {type: 'textbox', name: 'refSurname', label: 'Surname'}
                        ],
                        onsubmit: function(e) {    
                            ed.focus();
                            ed.selection.setContent('<pre class="language-' + e.data.refName + ' line-numbers">Data</pre>');
                        }
                    });
                }
            });

This is how my dialog box looks

Answer 1

I was using a beta version of tinymce(4.0b1). When I updated my library to 4.5.2, the issue was solved.