依赖YII输入框？ 我的错误在哪里？ 如何在dropDownList中添加Onchange事件？ 不使用控制器

Dependent YII Input Box? Where is my Mistake? How to add Onchange Event in dropDownList? I don't know how to add event in dropdown list.

View :

<div class="row">
        <?php echo $form->labelEx($model,'payment_method'); ?>
        <?php echo $form->dropDownList($model,'payment_method',array("Select","bank"=>"Bank","cash"=>"cash", onChange= 'javascript:myFunction()')) ?>
        <?php echo $form->error($model,'payment_method'); ?>
    </div>


<p id="demo"></p>

Java scrip :

<script>
function myFunction() {
    var x = document.getElementById("mySelect").value;
    document.getElementById("demo").innerHTML = "You selected: " + x;
}
</script>

You scripts contain syntax error. In you script onChange= should be 'onChange'=> and add a ; at the end of the same line. Change the line and try again

<?php echo $form->dropDownList(
    $model,
    'payment_method',
    array(
        "Select",
        "bank"=>"Bank",
        "cash"=>"cash",
    ),
    array(
        'onChange'=> 'javascript:myFunction()',
        'id'=>'mySelect'
    )
); ?>