js调用图片隐藏&显示实现代码_javascript技巧

var intTimeStep=20;
var isIe=(window.ActiveXObject)?true:false;
var intAlphaStep=(isIe)?5:0.05;
var curSObj=null;
var curOpacity=null;
function startObjVisible(objId)
{
curSObj=document.getElementById(objId);
setObjState();
}
function setObjState(evTarget)
{
if (curSObj.style.display==""){curOpacity=1;setObjClose();}
else{
if(isIe)
{
curSObj.style.cssText='DISPLAY: none;Z-INDEX: 1; FILTER: alpha(opacity=0); POSITION: absolute;';
curSObj.filters.alpha.opacity=0;
}else
{
curSObj.style.opacity=0
}
curSObj.style.display='';
curOpacity=0;
setObjOpen();
}
}
function setObjOpen()
{
if(isIe)
{
curSObj.filters.alpha.opacity+=intAlphaStep;
if (curSObj.filters.alpha.opacity<100) setTimeout('setObjOpen()',intTimeStep);
}else{
curOpacity+=intAlphaStep;
curSObj.style.opacity =curOpacity;
if (curOpacity<1) setTimeout('setObjOpen()',intTimeStep);
}
}
function setObjClose()
{
if(isIe)
{
curSObj.filters.alpha.opacity-=intAlphaStep;
if (curSObj.filters.alpha.opacity>0) {
setTimeout('setObjClose()',intTimeStep);}
else {curSObj.style.display="none";}
}else{
curOpacity-=intAlphaStep;
if (curOpacity>0) {
curSObj.style.opacity =curOpacity;
setTimeout('setObjClose()',intTimeStep);}
else {curSObj.style.display='none';}
}
}