onchange of a combobox changing the textbox value


I new to yii framework. i am working on a sample project and got stuck at a point

and I don’t know how to proceed from there. Please help me

in my active record form i have a combobox and a textfield. combobox is retriving data from a table.

my problem is i want the textbox to show the data according to combobox selection.

my table is having three columns

sid | share_name | exchange_rate

1 | gold | 100

2 | zinc | 30

3 | lead | 50

if I select the gold from the combobox it should display 100 in the textbox and if i select zinc from the combobox the textbox should display 30 and likewise.

i tried it do.but its not working, may be i am missing something…please help…

code for combobox

<?= $form->field($model,‘Share_Name’)->dropDownList(

                ArrayHelper::map(Sharename::find()-&gt;all(),'Share_Name','Share_Name'),array('onchange'=[b]&gt;<img src='http://www.yiiframework.com/forum/public/style_emoticons/default/huh.gif' class='bbc_emoticon' alt='???' />?[/b]), ['prompt'=&gt;'Select Share']

            ) ?&gt;

code for textbox

<?= Html::textInput( ‘Exchange_Rate’, ‘sid’, array(‘id’=>‘Exchange_Rate’)) ?>

‘onchange’=>‘here you can write the jQuery code’ so that you get the result as you want.