Drop down list onclick change value of input not working on chrome or opera

i have drop down item list. when i select an item. it should update input box on item prices. but it works perfectly on firefox and IE 9. dont work chrome or opera. anybody have an idea ?

{section name=n loop=$item_prices}

 <option onclick="javascript:document.getElementById('').value='${$item_prices[n].price}'" value="{$item_prices[n].id}" style="width:70px; border:1px solid #ccc; padding:5px; margin-left:auto; margin-right:auto;">{$item_prices[n].items}</option> 


<br  /><br  />

<td>Item price : </td>

<input type="text" name="item" id="item" value="" disabled="disabled" style="width:250px; color:#090; font-size:32px; font-weight:bold; outline:hidden; border:none; border-color:transparent; text-align: left; margin-left:17px; margin-right:auto;" />

first, you’re not passing in the ID of the field.

second, the onclick attribute does not need the javascript protocol (what else goes into an event attribute than javascript?)