Cant format request to squid?

We have a fully functioning squid server (2.5.STABLE1).
I need to script a monitoring tool to pass through it. To do this, I am
trying to pass a valid request to the squid proxy. I telnet to port
8080 and enter the following text:

GET http://www.microsoft.com/ HTTP/1.0
Host: www.microsoft.com
Accept: */*
User-Agent: WhatsUp Professional/1.0
Proxy-Connection: Keep-Alive

I press return twice at the end (for the two linefeeds) and Squid
*always* chokes and returns a HTTP/1.0 400 Bad Request - Some aspect of
the HTTP Request is invalid etc.

I have spent hours on this trying to get the syntax correct. I have
even sniffed packets from my browser to the proxy (which works) and
they look *exactly* the same! Can anyone put me out of my misery? Why
does SQUID barf on the text above?

Al Blake (Australia)