If blank space can be removed automitically?

I'm reading this question a little differently...

If you are asking how to remove the extra space when showing/hiding conditional tags, you need to make sure you include the space in your selection. If you just double-click a word, it won't select the space--leaving two spaces when the word is hidden. 

As a rule, I always select the trailing space except when not possible, such as the end of a sentence. 

For example, I would select the space after each program name:

Adobe FrameMaker InDesign is their most popular page-layout program.

Another option is not to use a space between the conditional words, but I find that more troublesome.

You have blanks not only in your document, but also your forum name is blank 😉

When you want to have only single spaces, while typing, open the Format menu and click Document and then Text Options. Activate Smart Spaces.

Now when you type, FrameMaker allows only a single space. Also when there are several spaces and you add an additional space, FrameMaker removes all but one space.

FrameMaker does not search across a document and changes all spaces.

What you could do:

In the Find/Replace pod select Regular Expressions.

Search for: ( ){2,}

There is only a single space between the brackets.

Then replace with another space.

Please test carefully before you do a "Replace all"! Make a backup copy!