I use Yahoo messenger to make long distance call to telephones but I do not find a way of saving my contact numbers

Sometimes you need to see the old text messages to see the important phone numbers or location of the meeting. Here's how to save the old messages are:
Click the Messenger menu and select Preferences.
From the list on the left, click on "Archive".
Check the box next to "Yes, save all my messages".
Click the OK button at the bottom of the window.
To view archived text messages:
Click the Contacts menu and select "Message Archive". At the bottom of the list of folders that appears on the left, click on SMS messages.
Click the mobile number you want to see.