<style>

.a1{

border-width:1px;

border-style:solid;

border-color:#FF0000;

width:180px;

}

.a2{

border:1px solid #006633;

}

</style>

<div class="a1">some text</div>

<div class="a2">some text again</div>

<script type="text/javascript">

alert($("div.a1").css("border-width")) work only in ie

alert($("div.a2").css("border")) not work in ie, ff

</script>

the first alert work only in ie, in ff = ["" or null]

the second alert: in ie6 = 'unknow' in ff = ["" or null]

verificated in ie(6) and ff (lastest version)