You need to spend time reviewing basic programming concepts. In the three threads you've posted, your code starts out almost completely incorrect, with mistakes that you should have picked up via error messages that matlab gives you.

In this question, you clearly aren't understanding how:

a) indexing works
b) matlab indexing works.

when you say:
lengthwords=index(line);

You're trying to use line (which is a string) to index into the variable index (which is a scalar).