language problem

language problem

I created this command:
\newcommand{\NewPart}[1]{\section*{\uppercase{#1}}}
and run it like this:
\NewPart{Personal details}{}
My problem is that instead of 'Personal details' I want to give a name in greek. I used babel and ran \selectlanguage{greek} but it is not enough. The letters remain in English. Can you give me any idea to handle my problem?
I am new here so excuse my several mistakes. This is my MWE:
\documentclass[paper=a4,fontsize=11pt]{scrartcl}                % KOMA-article class
\usepackage[iso-8859-7]{inputenc}
\usepackage{kerkis}
\usepackage{a4}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage[vcentering,dvips]{geometry}
\usepackage{calc}
\input{epsf.tex}
\usepackage[greek,english]{babel}                              
\usepackage{amsmath,amsfonts,amsthm}
\usepackage[svgnames]{xcolor} 
\usepackage{geometry}
\textheight=700px              
\usepackage{url}         
\usepackage{wrapfig}      
\frenchspacing            
\pagestyle{empty}                              

\usepackage{sectsty}                           
\sectionfont{%                                 
\usefont{OT1}{phv}{b}{n}%                  
\sectionrule{0pt}{0pt}{-5pt}{3pt}
}
\newlength{\spacebox}
\settowidth{\spacebox}{888888888}             
\newcommand{\sepspace}{\vspace*{1em}}          
\newcommand{\NewPart}[1]{\section*{\uppercase{#1}}}
\begin{document}
\selectlanguage{greek}
\NewPart{Personal details}{}
\end{document}
When I run the tex-file "Personal details" are written in English instead of Greek despite the fact that I have already changed the language.