[Tex/LaTex] How to join two arrows with (TikZ)

arrowsnodestikz-pgf

Possible Duplicate:
Merge arrows with TikZ

Is there a way to join two arrows? They should start from two different nodes, join and point to a third node. That would be great!

here I have a minimal example:

    \begin{tikzpicture}
\tikzstyle{every node}=[draw,shape=ellipse];
\node (node1) at (150:3) {x};
\node (node2) at ( 30:3) {y};
\node (node3) at ( 270:0) {z};

\path[->] (node1) edge [out=-20, in=100,draw=gruen,line width=2pt] (30:1);
\path[->] (node2) edge [out=200, in=80] (node3);
\end{tikzpicture}


I can try until I have an approximate coordinate where the join happens, but that would be a problem if I want to change the position of the nodes later.

EDIT

I would like to have it that way:

X ------             -------> Z
Y ------/


Not the best sketch. But as percusse mentioned, the linked question should answer my question, too.

Thanks to percusse! I didn't find that question .. here is what my solution now looks like:

    \begin{tikzpicture}
\tikzstyle{every node}=[draw,shape=ellipse];
\node (node1) at (150:3) {x};
\node (node2) at ( 30:3) {y};
\node (node3) at ( 270:0) {z};

\coordinate (zJoin) at ([yshift=0.5cm]node3.north);
\draw[->] (zJoin) -- (node3); % the arrow

\path (node1) edge [out=-20, in=100,draw=gruen,line width=2pt] (zJoin);
\path (node2) edge [out=200, in=80] (zJoin);
\end{tikzpicture}