大侠帮忙逐行给我解释下这段代码的意思
<script>
var  highlightcolor='#eafcd5';
//此处clickcolor只能用win系统颜色代码才能成功,如果用#xxxxxx的代码就不行,还没搞清楚为什么:(
var  clickcolor='#FF00FF';
function  changeto(){
source=event.srcElement;
if  (source.tagName=="TR"||source.tagName=="TABLE")
return;
while(source.tagName!="TD")
source=source.parentElement;
source=source.parentElement;
cs  =  source.children;
//alert(cs.length);
if  (cs[1].style.backgroundColor!=highlightcolor&&source.id!="nc"&&cs[1].style.backgroundColor!=clickcolor)
for(i=0;i<cs.length;i++){
cs[i].style.backgroundColor=highlightcolor;
}
}

function  changeback(){
if  (event.fromElement.contains(event.toElement)||source.contains(event.toElement)||source.id=="nc")
return
if  (event.toElement!=source&&cs[1].style.backgroundColor!=clickcolor)
//source.style.backgroundColor=originalcolor
for(i=0;i<cs.length;i++){
cs[i].style.backgroundColor="";
}
}

function  clickto(){
source=event.srcElement;
if  (source.tagName=="TR"||source.tagName=="TABLE")
return;
while(source.tagName!="TD")
source=source.parentElement;
source=source.parentElement;
cs  =  source.children;
//alert(cs.length);
if  (cs[1].style.backgroundColor!=clickcolor&&source.id!="nc")
for(i=0;i<cs.length;i++){
cs[i].style.backgroundColor=clickcolor;
}
else
for(i=0;i<cs.length;i++){
cs[i].style.backgroundColor="";
}
}
------解决方案--------------------
应该用英文单引号var clickcolor='#FF00FF';