为什么我check out 不了代码
D:\Program Files\TortoiseSVN\bin>svn co http://projectname.googlecode.com/svn/tr
unk
svn: E175002: Unable to connect to a repository at URL 'http://projectname.googl
ecode.com/svn/trunk'
svn: E175002: OPTIONS of 'http://projectname.googlecode.com/svn/trunk': could no
t connect to server (http://projectname.googlecode.com)