Thank you very much Supreme Postmaster. As you suggested I went into Tools/Customize/Keyboard/Edit/Edit Select. I then put the cursor in the"Press New Shortcut Key" box and pressed the spacebar. "Space" then appeared in the"Current Keys" box. Then, in order to implement the action, I found I had to click on "Assign" and then close. And Bingo - it worked! I am most grateful to you.