fix a jsp / css logic error

There is 2 conditions involved,lets take it as condition a and b
when
a b are false false,then show a image content.
a b are false true,then hide the image content,but show a message
a b are true false,then hide the image content,but show a message
a b are true true ,then hide the image content,but show a message

following is my particular code logic

<c:choose>
<c:when test ="${a eq condition}">
Text Message
</c:when>

<c:otherwise>
<c:choose>
<c:when test="${(b eq b1) or (b eq b2)}">
Text Message
</c:when>
<c:otherwise>
//display a image content link

</c:otherwise>
</c:choose>

</c:otherwise>
</c:choose>

however ,it always show the image link regardless , i think my code should work but it doesnt.
stuck at the bug for few hours,need your help to fix the issue. you need to work remotely as the display need complex environment set up