Programming :: Errors - Make Pop-up Reminders For The Simple Calendar Program?

First off, I'm completely new to bash scripting so forgive me if I make any egregious errors. I'm trying to make pop-up reminders for the simple calendar program when. This is what I have so far:

Code:
#!/bin/bash
# set the time format for when
#current="$(date +%I:%M %p)"
current="$(date +%-l%p)"
today=~/.when/today

[Code]....

When I run the script, gxmessage pops up and displays the correct information, but it does so for each line in "~/.when/today" that contains a time that matches the current system time (which would be three pop-ups at 10PM, according to the example). I want it to display the information only once. How can this be accomplished? Is a while loop even the right job for this?