"I don't think however that there is any harm in asking for salvation over & over again, if somebody has doubts in their mind that the first time they invited Jesus into their heart, 'didn't work'."
i think this is the experience of many people at first. i know that i was not sure that it had "stuck" when i first prayed as a young teenager and so i kept asking. i wasn't sure that i had "done it right".
my mother talks about going up to an altar call and praying the "sinners prayer" with some pastor at a church she visited as a young adult- early twenties. she knew that something was wrong in her life. he asked her afterwards "Now don't you feel better?" She said nothing to him at the time i am sure but she says now, "No! I felt worse!" It was not until years later that she actually got saved. I asked her why she thought that she didn't get saved when she prayed the first time. Her opinion is that she was not ready to actually sincerely commit her life to Christ.
I have been reading a bit lately about salvation... Faith alone... or is repentence required as well? does true faith include repentence?...