open CJuiDialog box on same page or overlap same page

I have used the CJuiDialog box in CGridView, when i clicked on button so open a new page in CJuidialog box but that dialog box opened on black page or not overlap the same page.

my button URl is other model/controller url.

'View Subjects' => array(

                               'url'=>'Yii::app()->createUrl("subjectMaster/courseSub", array("courseID"=>'.$course.',"semID"=>$data->academic_id,"acad_Year"=>'.$acad_year->academic_term_id.'))',



please help…