title: count value input field when click on a value jquery javascript
body: <p>i have a input field and links with values. when click on a link the value go to the input field. when clicking a other link the value is not count with the value that already is in the input field. example:</p>
  
  <pre><code>&lt;form name="odenen_form"&gt;
  &lt;input type="text"     
  class="input_text"name="odenen_miktar"id="odenen_miktar"    
  style="position:absolute;left:100px;top:50px;width:200px"&gt;
  &lt;/form&gt;
  
  &lt;a onClick="document.odenen_form.odenen_miktar.value+='10'"&gt;10&lt;/a&gt;
  &lt;a onClick="document.odenen_form.odenen_miktar.value+='20'"&gt;20&lt;/a&gt;
  </code></pre>
  
  <p>Now when i click on the first link the input field shows me 10
  when i click again on the first link the input field shows 1010</p>
  
  <p>Wat i want is 20 as result</p>