\documentclass{article} \usepackage{tikz} \usetikzlibrary{shapes,shadows,arrows} \usetikzlibrary{backgrounds} \begin{document} %line thickness styles: ultra thin, very thin, (thin), semithick, thick, very thick, ultra thick %line dash styles: loosely dashed, densely dashed, loosely dotted, densely dotted \tikzstyle{decision}=[diamond,draw,fill=gray!50] %\tikzstyle{arrow}=[draw,-latex',very thick] \tikzstyle{arrow}=[draw,-latex'] \tikzstyle{line}=[draw] \tikzstyle{cloud}=[draw=gray!0,very thick,block,rounded corners,fill=gray!2, minimum width=15mm, minimum height=15mm,node distance=5em] \tikzstyle{vagueblock}=[draw=gray!30,rectangle,rounded corners,fill=gray!30,text centered, minimum width=15mm, minimum height=15mm,node distance=5em] \tikzstyle{block}=[draw,rectangle,rounded corners,fill=gray!30,text centered, minimum width=15mm, minimum height=15mm,node distance=5em] \tikzstyle{empblock}=[draw,rectangle,rounded corners,minimum width=8cm,minim