when inserting new word how to stop next word from being deleted

[KAO1963]

I am editing a word document using word 2003. Initially I would click on a
space and insert a word and the text would automatically move over to make
room. I had to stop for awhile, when I came back to the work I tried to
insert and instead of the text moving over it started to delete the next word
in the sentence.

 

[garfield-n-odie [MVP]]

Press the Insert key once to switch between Overtype mode (what
you are in now) and Insert mode.