function cd {
    builtin cd $1
    PS1=${PS1# }
    PS1=${PS1#\*}
    if [ -e .svn ]; then
	DIFFS=`svn status| egrep "^M"`
	if [ -z "$DIFFS" ]; then
            PS1=" $PS1"
	    exit
	else
	    PS1="*$PS1"
	fi
    fi
}