function changekarte(y) {
 x=document.getElementById('karte');
 if (y == '-') {
   x.src='/karte/weltkarte-900px.jpg';
   umrechnung=1/26;
 }
 else if (y == '+') {
   x.src='/karte/weltkarte-1350px.jpg';
   umrechnung=1/39;
 } 
}

function clipsize(l,t,w,h) {
 c=document.getElementById("clip").style;
 c.top=t+"px";
 c.left=l+"px"; 
 c.width=w+"px";
 c.height=h+"px";
}

function posx(e) {
 if (e) { return e.pageX; } 
 else { return window.event.offsetX; }
}

function posy(e) {
 if (e) { return e.pageY; } 
 else { return window.event.offsetY; }
}

function zeichne(e) {
 if (!e) e = window.event;
 x2=posx(e);
 y2=posy(e);
 if (x1<=x2 && y1<=y2) { clipsize(x1,y1,x2-x1,y2-y1); }
 else  if (x2<=x1 && y1<=y2) { clipsize(x2,y1,x1-x2,y2-y1); }
 else  if (x2<=x1 && y2<=y1) { clipsize(x2,y2,x1-x2,y1-y2); }
 else  if (x1<=x2 && y2<=y1) { clipsize(x1,y2,x2-x1,y1-y2); }
}

x1=0;
y1=0;
umrechnung=1/27;
function messestart(e) {
 document.getElementById('anzeige').style.display='none';
 if (!e) e = window.event;
 x1=posx(e);
 y1=posy(e);
 clipsize(0,0,0,0);
 document.getElementById('clip').style.display='';
 document.getElementById('karte').onmousemove=zeichne;
 document.getElementById('clip').onmousemove=zeichne;
}

function messestop(e) {
 if (!e) e = window.event;
 x2=posx(e);
 y2=posy(e);
 x=x1-x2;
 y=y1-y2;
 l=Math.sqrt(x*x+y*y);

 document.getElementById('karte').onmousemove='';

 r=l*umrechnung;
 x=Math.round(r*10%10);
 k=Math.round(r*55);
 a=document.getElementById('anzeige');
 a.style.top=((y1+y2)/2-15)+'px';
 a.style.left=((x1+x2)/2-93)+'px';
 a.style.display='';
 t=Math.floor(r);
 if (x==10) { r++; x=0; }
 a.innerHTML='<b>Strecke:</b>&nbsp;'+k+'&nbsp;Kilometer<br/>'+
       '<b>Reisedauer:</b>&nbsp;'+Math.floor(r)+'&nbsp;Tagesritte,&nbsp;'+x+'&nbsp;Stunden<br/>'+
       '<i>1&nbsp;Tagesritt&nbsp;=&nbsp;10&nbsp;Stunden</i>';
  
 document.getElementById('clip').style.display='none';
 y1=0;
 x1=0; 
}