var j=55;
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;
	   if (j==55){
		 //alert (n)
		    i=aleatorio(0,n-3);
			  j=0
				i1=i+1;
		    i2=i+2;
		 }
   //for (i=0; i <n ; i++){
	    sy = Speed[i]*Math.sin(Cstep[i]);
			sy1 = Speed[i1]*Math.sin(Cstep[i1]);
			sy2 = Speed[i2]*Math.sin(Cstep[i2]);
	 		sx = Speed[i]*1;
			sx1 = Speed[i1]*1;
			sx2 = Speed[i2]*1;
	 		Xpos[i]+=sy;
			Xpos[i1]+=sy1;
			Xpos[i2]+=sy2;
	 		Ypos[i]+=sx;
			Ypos[i1]+=sx1;
			Ypos[i2]+=sx2;
			
	 		if (Ypos[i] > WinWidth-110){
				 if(ns6){
  				  capa=document.getElementById("si"+i);
				 }else{
	  			  capa=document.all["si"+i]
				 }
				 if(capa!=null){
				    capa.style.visibility = "hidden";
				 }
				 Ypos[i]=-100;
				 i+=3;
				 if(i>n-1){
				   i=0
				 }
	       Xpos[i]=aleatorio(-10,150);//Math.round(Math.random()*WinHeight);
	       Ypos[i]=-101;
	       Speed[i]=Math.random()*8+2;
	 		}
			if (Ypos[i1] > WinWidth-110){
				 if(ns6){
  				  capa=document.getElementById("si"+i1);
				 }else{
	  			  capa=document.all["si"+i1]
				 }
				 if(capa!=null){
				    capa.style.visibility = "hidden";
				 }						 
				 Ypos[i1]=-100;
				 i1+=3;
				 if(i1>n-1){
				   i1=1
				 }
	       Xpos[i1]=aleatorio(-10,150);//Math.round(Math.random()*WinHeight);
	       Ypos[i1]=-101;
	       Speed[i1]=Math.random()*8+2;
	 		}
			if (Ypos[i2] > WinWidth-110){
				 if(ns6){
  				  capa=document.getElementById("si"+i2);
				 }else{
	  			  capa=document.all["si"+i2]
				 }
				 if(capa!=null){
				 		 capa.style.visibility = "hidden";	
				 }
				 Ypos[i2]=-100;			 
				 i2+=3;
				 if(i2>n-1){
				    i2=2
				 }
	       Xpos[i2]=aleatorio(-10,150);//Math.round(Math.random()*WinHeight);
				 
	       Ypos[i2]=-101;
	       Speed[i2]=Math.random()*8+2;
	 		}
			
			
	 		if (Xpos[i] > 480){  //       limite inferior
			 if(Ypos[i]>WinWidth/2){
			   if(ns6){
  				  capa=document.getElementById("si"+i);
				 }else{
	  			  capa=document.all["si"+i]
				 }
				 if(capa!=null){
				    capa.style.visibility = "hidden";
			   }
	       Xpos[i]=0;
	       Ypos[i]=-100;
				 i+=3;
				 if(i>n-1){
				    i=0
				 }
				 Ypos[i]=-101
				 Xpos[i]=-51;
	       Speed[i]=Math.random()*8+2;
			 }else{
			   Xpos[i]=480;
  		 }	 
	 		}
	 		if (Xpos[i1] > 480){
			 if(Ypos[i1]>WinWidth/2){
			   if(ns6){
  				  capa=document.getElementById("si"+i1);
				 }else{
	  			  capa=document.all["si"+i1]
				 }
				 if(capa!=null){
				    capa.style.visibility = "hidden";
				 }		
	       Xpos[i1]=0;
	       Ypos[i1]=-100;
				 i1+=3;
				 if(i1>n-1){
				    i1=1
				 }
				 Ypos[i1]=-101
				 Xpos[i1]=-51;
	       Speed[i1]=Math.random()*8+2;
			 }else{
			   Xpos[i1]=480;
  		 } 
	 		}
			if (Xpos[i2] > 480){
			 if(Ypos[i2]>WinWidth/2){
			   if(ns6){
  				  capa=document.getElementById("si"+i2);
				 }else{
	  			  capa=document.all["si"+i2]
				 }
				 if(capa!=null){
				 		capa.style.visibility = "hidden";
				 }		
	       Xpos[i2]=0;
	       Ypos[i2]=-100;
				 i2+=3;
				 if(i2>n-1){
				    i2=2
				 }
				 Ypos[i2]=-101
				 Xpos[i2]=-51;
	       Speed[i2]=Math.random()*8+2;
			 }else{
			   Xpos[i2]=480;
  		 }	 
	 		}	 				
					
      if (ns6){
			   estelayer=document.getElementById("si"+i);
			   if(estelayer.style.visibility == "hidden"){
				     estelayer.style.visibility = "visible";
			   }
	 		   
				 estelayer.style.left=Ypos[i]+wscrll;
	    	 estelayer.style.top=Math.min(WinHeight,Xpos[i]);
				 estelayer1=document.getElementById("si"+i1);
         if(estelayer1.style.visibility == "hidden"){
				     estelayer1.style.visibility = "visible";
				 }
				 
				 estelayer1.style.left=Ypos[i1]+wscrll;
	    	 estelayer1.style.top=Math.min(WinHeight,Xpos[i1]);
				 estelayer2=document.getElementById("si"+i2);
         if(estelayer2.style.visibility == "hidden"){
				     estelayer2.style.visibility = "visible";
				 }
	 		   
				 estelayer2.style.left=Ypos[i2]+wscrll;
	    	 estelayer2.style.top=Math.min(WinHeight,Xpos[i2]);
			 				 
	 		}
   		else{
			   estelayer=document.all["si"+i]
			   if(estelayer.style.visibility == "hidden" && estelayer!=null){
				     estelayer.style.visibility = "visible";
			   }
	       
				 estelayer.style.left=Ypos[i]+wscrll;
	    	 estelayer.style.top=Math.min(WinHeight,Xpos[i]);
				 estelayer1=document.all["si"+i1]
 				 if(estelayer1.style.visibility == "hidden" && estelayer1!=null){
				     estelayer1.style.visibility = "visible";
				 }
	       
				 estelayer1.style.left=Ypos[i1]+wscrll;
	    	 estelayer1.style.top=Math.min(WinHeight,Xpos[i1]);
				 estelayer2=document.all["si"+i2]
				 if(estelayer2!=""){
				   if(estelayer2.style.visibility == "hidden" ){
				     estelayer2.style.visibility = "visible";
				   }
	       	 estelayer2.style.left=Ypos[i2]+wscrll;
	    	   estelayer2.style.top=Math.min(WinHeight,Xpos[i2]);				 
				 }				 
	 		} 
	 		Cstep[i]+=Step[i];
			Cstep[i1]+=Step[i1];
			Cstep[i2]+=Step[i2];
   setTimeout('fly()',20);
}
function aleatorio(infe,supe){
    inferior=infe;
		superior=supe;
    numPosibilidades = superior - inferior
    aleat = Math.random() * numPosibilidades
    aleat = Math.round(aleat)
    return parseInt(inferior) + aleat
} 
function is_valid(numeros, num) {
    for(j=0; j < numeros.length; j++) {
        if (num == numeros[j])
            return false;
    }
    return true;
}