How to add a class in yii form button submit
Try read manual or docs, or see examples
<?php echo $form->textField($model,'username', array('class' => 'myText', 'style' => 'width: 320px; border-radius: 10px;')); ?><?php echo CHtml::submitButton('Login', array('class' => 'submitClass', 'style' => 'width: 120px; border-radius: 10px;')); ?>http://www.yiiframework.com/doc/api/1.1/CHtml#submitButton-detail
very simple just add an array,in it you can put any html attribute in it
Like
<?php echo $form->textField($model,'username',array('class'=>'your class name','id'=>'Any Id You want to insert')); ?>