Can't recognize my flash to boot 10.7 installer

[yazan41]

hey all ,
my mac air can't recognize my flash drive to install 10.7 os x i used GUID and mac os (journaled) file system and verified my os files to the flash drive.
how to fix it ?

 

[maflynn]

Does the flash drive mount after your Mac boots up?

 

[yazan41]

no i mount the files on other mac and my mac air can't start up it shows message