get prev ID-value form input="text"

Question

I can find a way to get the id = "DropDownListA". But I have to get the id-value by using this

Somehow $(this).closest('input').attr('id') is not working

<td align="right">
 <div class="farvorit_field" id="DivDropDownListA">
 <input type="text" id="DropDownListA" name="customerGroup" value="" size="35">
  <a href="#" title='See farvorits customers.'>
   <img onClick="alert($(this).parent('a').siblings(':text').attr('id'));" src="../img/info.gif" border="0">
  </a>
 </div>
</td>

Answer 1

If it's an ID it is supposed to be the only one on the page, so why to make things complex and avoid the simplest $('#DropDownListA').attr('id')? If you absolutely have to use word this then use @ShankarSangoli's solution.

Answer 2

Use this.

$(this).parent().prev().attr('id')

.parent() will give anchor element and then calling .prev() on it will give the input element.

Demo