NPC Giving Skills

[NPC Giving Skills]

How can I hide skills from the skilltree, even if they are unlearned?? They will show up after the player learns the skill, and, of course, it cant dissapear

[NPC Giving Skills]

 

skill(<skill id>, <level>{, <flag>})

For <flag> make sure you put 0

 

Example:

skill(TF_THROWSTONE, 1, 0);

Didn't work, It still disappears

[NPC Giving Skills]

Hi guys, I would like to know how to create a NPC that gives skill for players, I already created this NPC but when I quit the game or even change map the skill just disappear.
 

Sorry for my bad english.