[texworks] New Command question from beginner

[Schor, Robert H]

I've just installed MiKTeX and have started writing a document about Getting Started with LabVIEW.  In this document, I talk about a Virtual Instrument, commonly abbreviated as VI.  To make the plural, I didn't want to use either VIs or VI's, but instead wanted to use VI\hspace{1pt}s, putting a little space between the VI and the "s".
Not wanting to type this string over and over again, I defined a New Command as follows:
\newcommand{VIs}{VI\hspace{1pt}s}
However, when I use it in my document, it "eats" white space that follows the command, causing a line such as "These \VIs will be" to be rendered as "These VIswill be" (with a 1 pt space between VI and s, but no space between s and "will").  On the other hand, if I build the space into the command itself, then "normal \VIs." is rendered as "normal VIs ."  (with the extra space before the period).
Is there a way to define the command so that the characters being output will "respect" subsequent white space?  [I've done a quick Google search, but am new enough to TeX and LaTeX to not know what search terms to use].
Bob Schor
P.S. - I've known about TeX and MetaFont for several decades, having read Knuth's original book on the subject.  It was only recently that one of my sons, a student at Caltech, asked me "Dad, what do you think about LaTeX", and I had to confess I'd never used it.  So he said "Try it, you'll like it", so I downloaded it and got some "Getting Started" help when he was home for Thanksgiving.  So far, I'm liking it ...

----- configuration info -----
TeXworks version : 0.4.3r857 (MiKTeX 2.9 64-bit)
Install location : C:/Program Files/MiKTeX 2.9/miktex/bin/x64/miktex-texworks.exe
Library path     : C:/Users/RSchor/AppData/Local/MiKTeX/2.9/TeXworks/0.4\
pdfTeX location  : C:/Program Files/MiKTeX 2.9/miktex/bin/x64/pdftex.exe
Operating system : Windows Microsoft Windows 7 Business Edition, 64-bit Service Pack 1 (build 7601)
Qt4 version      : 4.7.2 (build) / 4.7.2 (runtime)
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