first and last name can empty in contact ( Solved )

[henro]

Firstly i am sorry,
i have asked this in http://civicrm.stackexchange.com/questions/893/why-are-my-contacts-name-and-email-empty?noredirect=1#comment856_893
but , i did not solve,

i have so many contacts which the first name , last name , and email are empty .
please see my attached screen shot.

i don't know what my client have done in this site. as far i know , they import contact then import contribution data.

thanks for help

[henro]

thanks to all,

i have found , the cause is :
i try to update contacts via import ( update ), with the contacts data i will import only have external identifier


regards, henro