\documentclass[12pt, pagenumber=false, parskip=half,% 
               fromalign=right, fromphone=false,%  
               fromemail=false, fromurl=false,%
               fromlogo=false, fromrule=false,%
               backaddress=false, %
               foldmarks=false]{scrlttr2}
%%%%%%%%%%%%%%%%%%%%
% fromalign = right (right, center) -  Absenderfeld  formatiert.
% fromrule = afteraddress, false, aftername -  ein Linie wird nach  der Adresse gesetzt.
% backaddress = true (false) - Setzen einer Rücksendeadresse für Fensterumschläge
% fromphone   = true         - Setzen der Telefonnummer des Absenders
% fromemail   = true         - Setzen der eMail-Adresse des Absenders
% fromurl     = true         - Setzen einer Homepageadresse des Absenders
% fromlogo    = true         - Absenderlogo (Firmenlogo) wird in den Brief eingefügt
%%%%%%%%%%%%%%%%%%%%

\usepackage{eurosym}
\usepackage{textcomp}
\usepackage{ulem}
\usepackage{times}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}


\renewcommand*{\raggedsignature}{\raggedright}
\setkomavar{fromname}{Dr~Christian Urban}
\setkomavar{fromaddress}{Department of Informatics\\
  King's College London\\
  Strand, London WC2R 2LS\\
  United Kingdom}
\setkomavar{signature}{Dr Christian Urban\\ co-chair of the ITP 2015 conference}


\makeatletter
\@addtoplength{firstheadvpos}{20mm}
\makeatother

\begin{document}
\def\adrentry#1#2#3
{\begin{letter}{\mbox{}}
\opening{\bigskip\textbf{Certificate for the Registration Fee for the ITP 2015 Conference in Nanjing}}

\bigskip
This is to certify that 

\begin{center}
\textbf{#1}
\end{center}

\noindent paid

\begin{flushright}
\begin{tabular}{l@{\hspace{5mm}}r}
Total: & \uuline{#2}\\
\end{tabular}
\end{flushright}

\noindent 
\if #30{for the International Conference on Interactive Theorem Proving, which took place
from 24th until 27th of August in Nanjing, China.} \fi
\if #31{for the International Conference on Interactive Theorem Proving and the Isabelle Tutorial, 
which both took place from 21st until 27th of August in Nanjing, China.} \fi 
\if #32{for the International Conference on Interactive Theorem Proving and the Coq Tutorial, 
which both took place from 24th until 29th of August in Nanjing, China.} \fi 
\if #33{for the International Conference on Interactive Theorem Proving, as well as the 
Isabelle and Coq Tutorials, which all took place from 21th until 29th of August in Nanjing, China.} \fi 

\bigskip\bigskip\bigskip

\closing{\noindent{}Yours sincerely,\bigskip\mbox{}}
\end{letter}

}
\input{participants.db}
\end{document}