麻烦大家帮我看看这段js是什么意思，拜托各位了。。

<style type="text/css">
.fixTopLeft {
position: relative;
top: expression(showDiv . scrollTop);
left: expression(showDiv . scrollLeft);
z-index: 20;
border-bottom-width: 0px !important;
border-right-width: 0px !important;
}.fixTop {
position: relative;
top: expression(showDiv . scrollTop);
z-index: 10;
border-bottom-width: 0px !important;
border-right-width: 0px !important;
}.fixLeft {
position: relative;
left: expression(showDiv . scrollLeft);
z-index: 10;
border-bottom-width: 0px !important;
border-right-width: 0px !important;
}
</style><script type="text/javascript">
function fixTable(){ var fixRowCount=2;
var fixColCount=0; if(fixRowCount==0 && fixColCount==0)
return; var tableContainer=document.getElementById("showDiv"); _resizeTableContainer(tableContainer);
if(!tableContainer)
return;
var table=tableContainer.getElementsByTagName("TABLE");
if(!table || table.length==0)
return; var rows=table[0].rows;
var rowCount=rows.length;
if(fixRowCount>rowCount){
fixRowCount=rowCount;
} var rowSpans=new Array(fixColCount);
for(var i=0;i<fixColCount;i++){
rowSpans[i]=0;
}
var maxRowSpan=0;
var minRowSpan=0; var cssCells=[];
var cssNames=[];

for(var i=0;i<fixRowCount;i++){
var cells=rows[i].cells;
var spanInd=0;
var cellsLen=cells.length;
for(var j=0;j<cellsLen;j++){
var cell=cells[j];
if(maxRowSpan!=minRowSpan){
while(rowSpans[spanInd]>minRowSpan)
spanInd++;//行  >最小行 ，spanInd ++
} var cn=cell["className"];
if(!cn)
cn="";
else
cn+=" ";
if(spanInd<fixColCount)
cn+="fixTopLeft";
else
cn+="fixTop";
cssCells[cssCells.length]=cell;
cssNames[cssNames.length]=cn;
if(spanInd<fixColCount){
for(var k=0;k<cell.colSpan;k++){
var tSpan=rowSpans[spanInd++]+=cell.rowSpan;
if(tSpan>maxRowSpan)
maxRowSpan=tSpan;
}
}
}
minRowSpan++;
}
if(fixColCount>0){
for(var i=fixRowCount;i<rowCount;i++){
var cells=rows[i].cells;
var spanInd=0;
for(var j=0;spanInd<fixColCount;j++){
var cell=cells[j];
if(!cell){
break;
}
if(maxRowSpan!=minRowSpan){
while(rowSpans[spanInd]>minRowSpan)
spanInd++;
} var cn=cell["className"];

if(!cn)
cn=""; if(spanInd<fixColCount){
cn+=" fixLeft";
//cell.className=cn;
cssCells[cssCells.length]=cell;
cssNames[cssNames.length]=cn;
} if(spanInd<fixColCount){
for(var k=0;k<cell.colSpan;k++){
var tSpan=rowSpans[spanInd++]+=cell.rowSpan;
if(tSpan>maxRowSpan)
maxRowSpan=tSpan;
}
}
}
minRowSpan++;
}
} for(var i=0;i<cssCells.length;i++){
cssCells[i].className=cssNames[i];
} window.attachEvent('onresize',onResizeTableContainer);

}var DETECT_RESIZE_INTERVAL=100;
var MAX_DETECT_RESIZE_COUNT=20;
var DETECT_RESIZE_STABLE_COUNT=3;
var MAX_DETECT_COUNT=10;
var lastBodyWidth=0;
var lastBodyHeight=0;
var resizeState=0;
var detectCount=0;
function onResizeTableContainer(){
var width=document.body.offsetWidth;
var height=document.body.offsetHeight;
if(detectCount++ > MAX_DETECT_RESIZE_COUNT){
resetResizeVars();
return;
}
else if(resizeState==0 && !(lastBodyWidth==width && lastBodyHeight==height)){
resizeState=1;
}
else if(resizeState>0 && resizeState<DETECT_RESIZE_STABLE_COUNT && (lastBodyWidth==width && lastBodyHeight==height)){
resizeState++;
}

if(resizeState==DETECT_RESIZE_STABLE_COUNT){
_resizeTableContainer();
resetResizeVars();
}
else{
lastBodyWidth=width;
lastBodyHeight=height;
setTimeout(onResizeTableContainer,DETECT_RESIZE_INTERVAL);
}
}//数据重置
function resetResizeVars(){
lastBodyWidth=document.body.offsetWidth;
lastBodyHeight==document.body.offsetHeight;
detectCount=0;
resizeState=0;
}//table 容器包含了div里的所有内容
function _resizeTableContainer(){
var tableContainer=document.getElementById("showDiv");
tableContainer.style.width=835;
tableContainer.style.height= 280;
}</script>