View Compilation Error

0_0_23226672_6002.cpp: In function 'point crosspt(const point&, const point&, const point&, const point&)':
0_0_23226672_6002.cpp:58:28: error: 'w' was not declared in this scope
  return (p*a2-q*a1)/w(a2-a1);
                            ^