Populate textarea field with prototype - ajax

Question

Im struglling to autopopulating with prototype an textarea field. When costumer click <a href="#" onclick="SubmitPayshop();"/>GERAR</a>, they get response from a php file and should populate the textarea field.
The code above sucessfuly populate a specific DIV (commented in code), but i need to populate textarea <textarea style="width: 100%;height: 45px;" type="text" title="<?php echo $this->__('Payshop') ?>" class="input-text required-entry" id="pay_check_no" name="payment[check_no]" /></textarea>
Was triyng .update $('pay_check_no').value='***response from php***'. But no luck.
Could someone help me please?
Regards and thx
<script>
function SubmitPayshop()
{
new Ajax.Request('/payshop.php', {
method: 'get',
onSuccess: successFunc,
onFailure: failureFunc
});
}
function successFunc(response){
if (200 == response.status){
alert("A sua referência foi criada com sucesso!");
}
var container = $('pay_check_no');
var content = response.responseText;
container.update(content);
}
function failureFunc(response){
alert("Ocorreu um erro. Se deseja este método contate a loja diretamente." );
}
</script>
<ul class="form-list" id="payment_form_<?php echo $_code ?>" >
<div id="pay_check_no" name="payment[check_no]"></div>
<li>
<span class="input-box">
<textarea style="width: 100%;height: 45px;" type="text" title="<?php echo $this->__('Payshop') ?>" class="input-text required-entry" id="pay_check_no" name="payment[check_no]" /></textarea>
</span>
</li>
</ul>

Answer 1

You have two elements with same id="pay_check_no", and when you trying to change $('pay_check_no').value looks like $('pay_check_no') refers to 'div' element not to input, just try to use different ids

Answer 2

Try using $('pay_check_no').value
Also ID should be unique
<div **id="pay_check_no"** name="payment[check_no]"></div>
<li>
<span class="input-box">
<textarea ...**id="pay_check_no"** name="payment[check_no]" /></textarea>
</span>
</li>