How do I make this if then else script
<p>I've been trying to make this <strong>if then else script</strong> but its wrong every time.</p>

<p>I am brand new at this, maybe I have taken more than I can chew but I am trying to make a script that runs at launch that does this</p>

<p>If file exists /Users/Bob/Library/Safari/Bookmarks.plist </p>

<p>then do nothing</p>

<p>if file does not exist ( i assume this is "else") then move file from /Library/Application\ Support/Bookmarks.plist to /Users/Bob/Library/Safari/Bookmarks.plist </p>

<p>Any feedback is greatly appreciated, thanks in advance.</p>