How to refresh image alone in a portlet upon clicking some button

[laxmiraghu]

In my registration page, i've implemneted JCaptcha. The problem is sometimes it's very difficult to read the image. So, we are planning to provide a button named 'REFRESH' next to the jcaptcha image and upon clicking REFRESH button, it has to refresh only the jcaptcha image not the entire page/portlet. How can we do that?

Currently i'm doing this way in my jsp:

<td><img id="siimage" src="/spring-portlet-sample/jcaptcha" alt="Dynamic Verification Code" border="5" >
                                             <a  style="border-style: none" href="#" title="Refresh Image" onclick='document.getElementById("siimage").src="/spring-portlet-sample/jcaptcha"; return false;'><img src="/jetspeed/decorations/portlet/jetspeed/images/refresh.gif" alt="Reload Image" onclick="this.blur();"  border="0" align="bottom" /></a>
                                             </td>

IN the image url, jcaptcha is a servlet.

If anybody know the solution, please share.

Thank you.

[cmelgar]

<a  style="border-style: none" href="#" title="Refresh Image" onclick='document.getElementById("siimage").src="/spring-portlet-sample/jcaptcha"; return false;'><img src="/jetspeed/decorations/portlet/jetspeed/images/refresh.gif" alt="Reload Image" onclick="this.blur();"  border="0" align="bottom" /></a>

I think you are pretty close already. You probably just need to add something like a # + a randomly generated number onto the end of the update image source to avoid caching.

e.g. /spring-portket-sample/jcaptcha#987938279

[laxmiraghu]

Thanks Chris. Yes .... by adding a randomly generated number, i could able to ahieve what i wanted.

Thanks again.