extern void object::AdvancedTowe()
{
	errmode(0);
	object  tower;               // info. about tower
	object  station;             // info. about station
	object  obj, item,cell; 
	point   dest,scrap, storage;
	int j=5, err,i;
	float dist, pl, xt,yt,x,y;
	while(true) {
		do
		{
			tower = radar(DefenseTower,0,360,j-5,j);
			j+=5;
			if (tower != null){
				if (tower.energyCell.energyLevel >= 0.4) {
					tower = radar(WayPoint,0,1,0,1);
				}
			}
			if (j >= 400){
				j=5;
				wait(30);
			}
		}
		while ( tower == null);
		message("Tower Needs power at X=" + tower.position.x +" Y="+tower.position.y,DisplayInfo);
		item=radar(PowerStation);
		if(item==null) { item = radar(SpaceShip);}
		dist=distance(tower.position,item.position) + distance(position,tower.position);
		if(category == LeggedGrabber) { pl = (0.05 + 1.1*(dist*0.0008)); }
		if(category == WheeledGrabber) { pl = (0.10 + 1.5*(dist*0.0016)); }
		if(category == TrackedGrabber) { pl = (0.10 + 1.5*(dist*0.0025)); }
		if(energyCell.category == NuclearCell) { pl = pl * 0.1;}
		message("Estimated Safe power needed is :"+(pl*100)+"% of cell." ,DisplayInfo);
		message("Current Cell level is:"+ (energyCell.energyLevel * 100) +"%" ,DisplayInfo);
		if(energyCell.energyLevel < pl and energyCell.category != NuclearCell and (radar(PowerStation)) != null) {
			j=5;
			do
			{
				item = radar(PowerStation,0,360,j-5,j);
				j+=5;
				if (item != null) { err = goto(item.position);
					if(err != 0){item = radar(WayPoint,0,1,0,1);}
				}
				if (j >= 600){
					j=5;
					message("PowerStation(s) are blocked!",DisplayWarning);
					wait(30);
				}
				
			}
			while (item == null);
			if (item != null){
				message("The Bot is recharging its power cells.",DisplayInfo);
				while ( energyCell.energyLevel < 1 )
				{
					wait(1);           
				}
				
			}
		}
		else {
			if (category != Subber) {
				if(energyCell.energyLevel < pl ) {
					message("The Bot is changing power cells.",DisplayInfo);
					j= 5;
					do{
						item = radar(PowerCell,0,360,j-5,j);
						if (item == null) {item = radar(NuclearCell,0,360,j-5,j);}
						j+=5;
						if (item != null) {if (item.energyLevel <= 0.8) {
								item = radar(WayPoint,0,1,0,1);}
						}
						if (j >= 400){
							j=5;
							message("Bot Cannot find any energy cells.",DisplayInfo);
							wait(30);
							
						}
					}
					while ( item == null );
					
					do{
						err = goto(item.position);
						if (err != 0) { 
							message("powercell get error.. trying again.",DisplayInfo);
							turn(120);
							move(15);
						}
					}
					while(err !=0 );
					grab(InFront);     // take the new cell in front
					drop(Behind);      // and drop it behind
					
					grab(EnergyCell);  // take the cell from the bot
					drop(InFront);     // and drop it in front
					
					grab(Behind);      // take the new cell
					drop(EnergyCell);  // and drop it on the bot
					
				}
				else{ if(energyCell.energyLevel < pl ) {
					item = radar(SpaceShip);
					goto(item.position);
					message("Subber needs a Cell change at SpaceShip.",DisplayError);}
				}
			}
		}
		drop(InFront);
		j=5;
		do{
			item = radar(PowerCell,0,360,j-5,j);
			if (item == null) { item = radar(NuclearCell,0,360,j-5,j);}
			j+=5;
			if (item != null) {if (item.energyLevel <= 0.8) {
					item = radar(WayPoint,0,1,0,1);}
			}
			if (j >= 400){
				j=5;
				message("Bot Cannot find any energy cells.",DisplayInfo);
				wait(30);
				
			}
		}
		while ( item == null );
		
		goto(item.position);
		grab();
		goto(tower.position);  
		turn(90);
		drop();
		turn(-90);
		grab();
		turn(-90);
		drop();
		turn(180);
		grab();
		turn(-90);
		drop();
		turn(-90);
		cell = radar(PowerCell,0,360,0,5);
		grab();
		turn(-90);
		if(cell != null and radar(PowerStation) != null ){
			message("The old cell is rechargable and there is a PowerStation.", DisplayInfo);
			j=5;
			do
			{
				item = radar(PowerStation,0,360,j-5,j);
				j+=5;
				if (item != null) { err = goto(item.position);
					if(err != 0){item = radar(WayPoint,0,1,0,1);}
				}
				if (j >= 600){
					j=5;
					wait(30);
				}
				
			}
			while (item == null);
			if (item != null){
				message("The Bot is recharging the old power cell.",DisplayInfo);
				do {
					motor(-1,-0.3);
					wait(2);
					err=goto(item.position);
					
				}
				while (err != 0);
				while ( cell.energyLevel < 1 )
				{
					wait(1);           
				}
				goto(space());
				drop();
				
			}
			
		}
		else{
			goto(space());
			drop();
		}
	}
}