请看一面代码.想改成.只显示一个层.然后从右向左飞.飞一次就行了.速度试中就行?

<body>
<script language="JavaScript1.2">
grphcs=new Array(5) //设置调用的图片数量、名称及路径
Image0=new Image();
Image0.src=grphcs[0]="images/mj4.gif"Amount=1; //设置在页面中随机显示的图片数量
Ypos=new Array();
Xpos=new Array();
Speed=new Array();
Step=new Array();
Cstep=new Array();ns=(document.layers)?1:0;
ns6=(document.getElementById&&!document.all)?1:0;
ie=document.all
if (ns){
for (i = 1; i < Amount; i){var P=Math.floor(Math.random()*grphcs.length);
rndPic=grphcs[P];
document.write("<LAYER NAME='sn"+i+"' LEFT=0 TOP=0><img src="+rndPic+"></LAYER>");}}
else{ document.write('<div style="position:absolute;top:0px;left:0px"><div style="position:relative">');
for (i = 0; i < Amount; i++){var P=Math.floor(Math.random()*grphcs.length);
rndPic=grphcs[P];
document.write('<img id="si'+i+'" src="'+rndPic+'" style="position:absolute;top:0px;left:0px" >');}
document.write('</div></div>');}
WinHeight=(ns||ns6)?window.innerHeight-70:window.document.body.clientHeight;
WinWidth=(ns||ns6)?window.innerWidth:window.document.body.clientWidth;
for (i=0; i < Amount; i++){                                                                
 Ypos[i] = Math.round(Math.random()*WinHeight);
 Xpos[i] =0;
 Speed[i]= Math.random()*5+1;
 Cstep[i]=0;
 Step[i]=Math.random()*0.1+0.05;}
function fly(){
var WinHeight=(ns||ns6)?window.innerHeight:window.document.body.clientHeight;
var WinWidth=(ns||ns6)?window.innerWidth-70:window.document.body.clientWidth;
var hscrll=(ns||ns6)?window.pageYOffset:document.body.scrollTop;
var wscrll=(ns||ns6)?window.pageXOffset:document.body.scrollLeft;
for (i=0; i < Amount; i++){
sy = 2*Math.sin(Cstep[i]);
sx = 2*2;
Ypos[i]+=sy;
Xpos[i]+=sx; 
if (Xpos[i] > WinWidth){
Ypos[i]=Math.round(Math.random()*WinHeight);
Xpos[i]=-60;
Speed[i]=0;return;}
if (ns){document.layers['sn'+i].left=0;
document.layers['sn'+i].top=Ypos[i];}
else if (ns6){
document.getElementById("si"+i).style.left=0;
document.getElementById("si"+i).style.top=Math.min(WinHeight,Ypos[i]);}
else{
eval("document.all.si"+i).style.left=Xpos[i];
eval("document.all.si"+i).style.top=Ypos[i]; } 
Cstep[i]+=Step[i]; }
setTimeout('fly()',20); }
if (ie||ns||ns6)
window.onload=fly
//-->
</script>
</body>

解决方案 »

  1.   

    <script language="JavaScript1.2">
    grphcs=new Array(5) //设置调用的图片数量、名称及路径
    Image0=new Image();
    Image0.src=grphcs[0]="images/mj4.gif"Amount=1; //设置在页面中随机显示的图片数量
    Ypos=new Array();
    Xpos=new Array();
    Speed=new Array();
    Step=new Array();
    Cstep=new Array();ns=(document.layers)?1:0;
    ns6=(document.getElementById&&!document.all)?1:0;
    ie=document.all
    if (ns){
    for (i = 1; i < Amount; i){var P=Math.floor(Math.random()*grphcs.length);
    rndPic=grphcs[P];
    document.write("<LAYER NAME='sn"+i+"' LEFT=0 TOP=0><img src="+rndPic+"></LAYER>");}}
    else{ document.write('<div style="position:absolute;top:0px;left:0px"><div style="position:relative">');
    for (i = 0; i < Amount; i++){var P=Math.floor(Math.random()*grphcs.length);
    rndPic=grphcs[P];
    document.write('<img id="si'+i+'" src="'+rndPic+'" style="position:absolute;top:0px;left:0px" >');}
    document.write('</div></div>');}
    WinHeight=(ns||ns6)?window.innerHeight-70:window.document.body.clientHeight;
    WinWidth=(ns||ns6)?window.innerWidth:window.document.body.clientWidth;
    for (i=0; i < Amount; i++){                                                                
     Ypos[i] = Math.round(Math.random()*WinHeight);
     Xpos[i] = WinWidth;//Math.round(Math.random()*WinWidth);
     Speed[i]= Math.random()*5+1;
     Cstep[i]=0;
     Step[i]=Math.random()*0.1+0.05;}
    function fly(){
    var WinHeight=(ns||ns6)?window.innerHeight:window.document.body.clientHeight;
    var WinWidth=(ns||ns6)?window.innerWidth-70:window.document.body.clientWidth;
    var hscrll=(ns||ns6)?window.pageYOffset:document.body.scrollTop;
    var wscrll=(ns||ns6)?window.pageXOffset:document.body.scrollLeft;
    for (i=0; i < Amount; i++){
    sy = Speed[i]*Math.sin(Cstep[i]);
    sx = Speed[i]*2;
    Ypos[i]+=sy;
    Xpos[i]-=sx; 
    if (Xpos[i] < 0){
    Ypos[i]=Math.round(Math.random()*WinHeight);
    Xpos[i]=-60;
    Speed[i]=Math.random()*5+1;}
    if (ns){document.layers['sn'+i].left=Xpos[i]+wscrll;
    document.layers['sn'+i].top=Ypos[i];}
    else if (ns6){
    document.getElementById("si"+i).style.left=Xpos[i]+wscrll;
    document.getElementById("si"+i).style.top=Math.min(WinHeight,Ypos[i]);}
    else{
    eval("document.all.si"+i).style.left=Xpos[i]+wscrll;
    eval("document.all.si"+i).style.top=Ypos[i]; } 
    Cstep[i]+=Step[i]; }
    setTimeout('fly()',20); }
    if (ie||ns||ns6)
    window.onload=fly
    //-->
    </script>
      

  2.   

    控制速度Speed=10<script language="JavaScript1.2">
    Image0=new Image();
    Image0.src="images/mj4.gif"ns=(document.layers)?1:0;
    ns6=(document.getElementById&&!document.all)?1:0;
    ie=document.all;
    if (ns)
    {
    document.write("<LAYER NAME='sn1' LEFT=0 TOP=0><img src="+Image0.src+"></LAYER>");
    }
    else
    {
    document.write('<div style="position:absolute;top:0px;left:0px"><div style="position:relative">');
    document.write('<img id="si1" src="'+Image0.src+'" style="position:absolute;top:0px;left:0px" >');
    document.write('</div></div>');
    }
    WinHeight=(ns||ns6)?window.innerHeight-70:window.document.body.clientHeight;
    WinWidth=(ns||ns6)?window.innerWidth:window.document.body.clientWidth;
    Ypos = WinHeight/2;
    Xpos = WinWidth;
    Speed= 4;
    Cstep=0;
    Step=Math.random()*0.1+0.05;
    function fly()
    {
    var WinHeight=(ns||ns6)?window.innerHeight:window.document.body.clientHeight;
    var WinWidth=(ns||ns6)?window.innerWidth-70:window.document.body.clientWidth;
    var hscrll=(ns||ns6)?window.pageYOffset:document.body.scrollTop;
    var wscrll=(ns||ns6)?window.pageXOffset:document.body.scrollLeft; sy = Speed*Math.sin(Cstep);
    sx = Speed*2;
    Ypos+=sy;
    Xpos-=sx; 
    if (Xpos < 0)
    {
    Ypos=WinHeight/2;
    Xpos=WinWidth;
    }
    if (ns)
    {
    document.layers['sn1'].left=Xpos+wscrll;
    document.layers['sn1'].top=Ypos;
    }
    else if (ns6)
    {
    document.getElementById("si1").style.left=Xpos+wscrll;
    document.getElementById("si1").style.top=Math.min(WinHeight,Ypos);
    }
    else
    {
    eval("document.all.si1").style.left=Xpos+wscrll;
    eval("document.all.si1").style.top=Ypos; 
    } 
    Cstep+=Step;  setTimeout('fly()',20); 
    }if (ie||ns||ns6)
    window.onload=fly
    //-->
    </script>