java script

can anybody explain below code:

function expand(curHeader){

curDrawer=curHeader.nextSibling

curDrawer.style.display=""

currentTR=curHeader.firstChild.firstChild

currentTR.firstChild.nextSibling.innerHTML="<img src=\"<%=contextPath %>/img/up_arrow.gif\" onclick=\"toggleDisplay()\" style=\"cursor:hand\" />"

currentTR.firstChild.nextSibling.valign="bottom"

var temp=currentTR.firstChild.innerHTML

currentTR.firstChild.innerHTML="<b>"+temp+"</b>"

}

function expandAll(){

curHeader=event.srcElement.parentNode.parentNode.parentNode.parentNode

while(curHeader.nextSibling.nextSibling){

curHeader=curHeader.nextSibling.nextSibling

if (curHeader.nextSibling.style.display=="none")

expand(curHeader)

}

}

[829 byte] By [kumar@javaa] at [2007-11-27 2:34:49]