Why does this produce a syntax error?

for(j=i+1;j<nodez.length;j++){
   nodeB = nodez[j];
   dx = nodeB._x – nodeA._x;
   dy = nodeB._y – nodeA._y;
   dist = Math.sqrt(dx*dx+dy*dy);

syntax error is on dx = …, and dy = …

any idears? i got this from bit-101, trying to get into mathmatics…