View Compilation Error

0_0_29716306_20090.cpp: In function 'bool ok(double)':
0_0_29716306_20090.cpp:6:17: error: 't' was not declared in this scope
  double x_=x+vx*t,y_=y+vy*t,z_=z+vz*t;
                 ^
0_0_29716306_20090.cpp:7:5: error: 'z_' was not declared in this scope
  if(z_>=0&&z_<=h&&x_*x_+y_*y_<=r) return true;
     ^
0_0_29716306_20090.cpp:7:25: error: 'y_' was not declared in this scope
  if(z_>=0&&z_<=h&&x_*x_+y_*y_<=r) return true;
                         ^