<div id=kk>
<iframe src=http://www.google.com></iframe>
</div>
<button onclick='kk.innerHTML=""'> clear </button>
<iframe src=http://www.google.com></iframe>
</div>
<button onclick='kk.innerHTML=""'> clear </button>
<frame name="leftFrame" scrolling="NO" noresize src="about:<button onclick='top.kk.innerHTML=null'>clear</button>">
<frame name="mainFrame" src="about:blank">
</frameset>