Basic Question

["Allan T. Parreno" <allan hopper iloilo fapenet org>]

Hi, Any Idea on how to parse this file?

Example At the sample.txt file the content is
one
two
three
four
five

six
seven
eight
nine
ten
 
Question: How do i parse it to look this way.
one:two:three:four:five
six:seven:eight:nine:ten


Thanks in advance for the great help!