asymptote.sty not found

Question

Running a sample code with \usepackage{asymptote}, I get asymptote.sty not found. I have installed ProTeXt which installed MikTeX 2.9. Now, to resolve this issue, I installed asypictureb package the definiton given as User-Friendly Integration of Asymptote into LaTeX by MikTeX Package Manager (I couldn't find a package named asymptote). Even after installation and rebuilding the system, I get the same error. What should I do?

The Code:

\documentclass{standalone}
\usepackage{asymptote}

\begin{document}

\begin{asy}[width=10cm,height=10cm]
import three;

currentprojection=perspective(300,-650,500,center=true);


// define two types of ions
surface iona = scale3(20)*unitsphere;
surface ionb = scale3(25)*unitsphere;

// surface properties and color of the ions
material White = material(diffusepen=gray(0.4),emissivepen=gray(0.6));
material Red = material(diffusepen=red,emissivepen=lightred);

// style of lines connecting ions
pen thick=linewidth(2);

for(int x=-1; x<2; ++x) {
  for(int y=-1; y<2; ++y) {
    for(int z=-1; z<2; ++z) {
      draw(shift(100*(x,y,z))*iona,White);
    }
  }
}

for(int x=-1; x<2; ++x) {
  for(int y=-1; y<2; ++y) {
    for(int z=-1; z<2; ++z) {
      if(x<1) draw(100*(x,y,z)--100*(x+1,y,z),thick);
      if(y<1) draw(100*(x,y,z)--100*(x,y+1,z),thick);
      if(z<1) draw(100*(x,y,z)--100*(x,y,z+1),thick);
    }
  }
}

for(int x=-1; x<2; x+=2) {
  for(int y=-1; y<2; y+=2) {
    for(int z=-1; z<2; z+=2) {
      draw(shift(50*(x,y,z))*ionb,Red);
    }
  }
}
\end{asy}

\end{document}