//Put start page url here.
goTo="#";

//Size of stationary ball.
F=1;

//Moving ball sizes. Add to array for more balls, min 2.
S=new Array(90,20,30,40,50,90)

//Speeds.
min=10;
max=30;

//Alter nothing past here. Co-ordinates will be lost!
n6=(document.getElementById&&!document.all);
n4=(document.layers);
ie=(document.all);

d=(n4||ie)?'document.':'document.getElementById("';
a=(n4||n6)?'':'all.';
n6r=(n6)?'")':'';
s=(n4)?'':'.style'; 
TY=0;
TX=0;
I=new Array();
P=new Array();
HT=new Array();
HY=new Array();
HX=new Array();
Y=new Array();
X=new Array();
A=new Array();
PY=new Array();
PX=new Array();
CR=new Array();
D=new Array();
B=new Array();
SP=new Array();
SP2=new Array();
Q=new Array();
CY=new Array();
CX=new Array();
IL=new Array();
ILS=new Array();
TD=new Array();
SH=new Array();
L=new Array();
p1x=new Array();
p1y=new Array();
p2x=new Array();
p2y=new Array();
CY=new Array();
CX=new Array();
FDS=new Array();
DS=new Array();

if (ie){
document.write("<a href='"+goTo+"'><img src='elems/shim.gif' border='0' height='"+F+"' width='"+F+"' id='still' style='position:absolute;top:300px;left:438px;width:"+F+";height:"+F+"'></a>");
}
if (n6){
document.write("<div id='still' style='position:absolute;top:179px;left:438px;width:"+F+";height:"+F+";cursor:move'>");
document.write("<a href='"+goTo+"'><img src='ballB.gif' border='0' height='"+F+"' width='"+F+"'></a>");
document.write("</div>");
}
if (n4){
document.write("<layer name='still' top=200 left=450>");
document.write("<a href='"+goTo+"'><img src='ballC.gif' border='0' height='"+F+"' width='"+F+"'></a>");
document.write("</layer>");
}
for (i=0; i < S.length; i++){
if (ie){
document.write("<img id='move"+i+"' src='ballA.gif' height='"+S[i]+"' width='"+S[i]+"' style='position:absolute;top:0px;left:0px;height:"+S[i]+";width:"+S[i]+"'>");
}
if (n6){
document.write("<div id='move"+i+"' style='position:absolute;top:0px;left:0px;height:"+S[i]+";width:"+S[i]+"'>");
document.write("<img src='ballA.gif' height='"+S[i]+"' width='"+S[i]+"'>");
document.write("</div>");
}
if (n4){
document.write("<layer name='move"+i+"' top=0 left=0>");
document.write("<img src='ballA.gif' height='"+S[i]+"' width='"+S[i]+"'>");
document.write("</layer>");
}

Y[i]=10;
X[i]=100;
D[i]=300;
SP[i]=min+Math.floor(Math.random()*max);
SP2[i]=SP[i];
}


function Move(){
H=(n4||n6)?window.innerHeight:document.body.clientHeight;
W=(n4||n6)?window.innerWidth:document.body.clientWidth;
T1=eval(d+a+"still"+n6r+s);
R1=F/2;
T1.top=H/2-R1;
T1.left=W/2-R1;
//center of stationary ball!! 
TY=(ie)?T1.pixelTop+F/2:parseInt(T1.top)+F/2;
TX=(ie)?T1.pixelLeft+F/2:parseInt(T1.left)+F/2;
for (i=0; i < S.length; i++){
T2=eval(d+a+"move"+i+n6r+s);
R2=S[i]/2;
CR[i]=R2+R1;
//center of moving balls!!
PY[i]=(ie)?T2.pixelTop+S[i]/2:parseInt(T2.top)+S[i]/2;
PX[i]=(ie)?T2.pixelLeft+S[i]/2:parseInt(T2.left)+S[i]/2;
//Angle between center of balls and still!!
ay=PY[i]-TY;
ax=PX[i]-TX;
A[i]=Math.atan2(ay,ax)*180/Math.PI;
if (A[i] < 0) A[i]+=360;
//Shortest distance between centre's of stationary and moving balls!!
dx=TY-PY[i];
dy=TX-PX[i];
DS[i]=Math.sqrt(dx*dx+dy*dy);
FDS[i] = Math.floor(DS[i]);
Q[i]=(FDS[i]-CR[i]);
if (Q[i] < 0) Q[i]=0;
//The following is based on a standard line/circle intersection routine. 
B[i]=R1/R2+1;
CY[i]=PY[i]-(DS[i]/B[i])*Math.sin(A[i]*Math.PI/180);
CX[i]=PX[i]-(DS[i]/B[i])*Math.cos(A[i]*Math.PI/180);
//Line start point!! 
p1y[i]=CY[i];
p1x[i]=CX[i];
//Line end point!!
p2y[i]=CY[i]+1*Math.sin(D[i]*Math.PI/180);
p2x[i]=CX[i]+1*Math.cos(D[i]*Math.PI/180);
L[i]=(p2x[i]-p1x[i])*(p2x[i]-p1x[i])+(p2y[i]-p1y[i])*(p2y[i]-p1y[i]);
//Travelling towards if SH is less than zero.
SH[i]=2*((p2x[i]-p1x[i])*(p1x[i]-TX)+(p2y[i]-p1y[i])*(p1y[i]-TY));
TD[i]=TX*TX+TY*TY+p1x[i]*p1x[i]+p1y[i]*p1y[i]-2*(TX*p1x[i]+TY*p1y[i])-R1*R1;//OK!
//Contact possible if IL is greater than zero!
IL[i]=SH[i]*SH[i]-4*L[i]*TD[i];
ILS[i]=Math.sqrt(IL[i]);
HT[i]=(-SH[i]-ILS[i])/(2*L[i]);
HX[i]=p1x[i]+HT[i]*(p2x[i]-p1x[i]);//Contact point x.
HY[i]=p1y[i]+HT[i]*(p2y[i]-p1y[i]);//Contact point y.  
//Required angle.
a1= HY[i]-TY;
a2= HX[i]-TX;
I[i]=Math.atan2(a1,a2)*180/Math.PI;
if (I[i] < 0) I[i]+=360;
//Distance to impact point.
d1=HY[i]-CY[i];
d2=HX[i]-CX[i];
P[i]=Math.floor(Math.sqrt(d1*d1+d2*d2)*2);
//Error adjust. For this situation only!
if (Q[i] <= 0) Q[i]=0;
if (SP[i] == 0) Q[i]=0;
E=(R1 > R2)?SP[i]*2:SP[i];

if ((P[i] <= E) && (IL[i] > 1) && (SH[i] < 0)){
SP[i]=0;
Y[i]=(TY-R2)+CR[i]*Math.sin(I[i]*Math.PI/180);
X[i]=(TX-R2)+CR[i]*Math.cos(I[i]*Math.PI/180);
}
if ((Q[i] == 0) && (SH[i] <= -1)){
D[i]=A[i]*2-180-D[i];
SP[i]=SP2[i];
}
if (D[i] < 0) D[i]+=360;
Y[i]+=SP[i]*Math.sin(D[i]*Math.PI/180);
X[i]+=SP[i]*Math.cos(D[i]*Math.PI/180);
VB=180-D[i];
HB=0-D[i];
//Edge rebounds!
if(Y[i]<1){Y[i]=1;D[i]=HB}  
if(Y[i]+S[i]>H){Y[i]=H-S[i];D[i]=HB}  
if(X[i]<1){X[i]=1;D[i]=VB}      
if(X[i]+S[i]>W){X[i]=W-S[i];D[i]=VB} 
//Corner rebounds! not necessary but looks nice.
if((Y[i]<1)&&(X[i]<1)){Y[i]=1;X[i]=1;D[i]=45}
if((Y[i]<1)&&(X[i]+S[i]>W)){Y[i]=1;X[i]=W-S[i];D[i]=135}
if((Y[i]+S[i]>H)&&(X[i]<1)){Y[i]=H-S[i];X[i]=1;D[i]=315}
if((Y[i]+S[i]>H)&&(X[i]+S[i]>W)){Y[i]=H-S[i];X[i]=W-S[i];D[i]=225}
T2.top=Y[i];
T2.left=X[i];
}//end loop!
setTimeout('Move()',40);
}
//-->