[SCRIPT] A question of variables

[The chaser]

Hi, forum.
Maybe I'm being heavy with all my questions, but it's just that i didn't find what i was searching, and i think that in this forum someone will know it.

How can i make this:
If you carry a hammer, wooden planks appear when crossing a script area.
If you don't (the most interesting for me) there are no wooden planks and a monster chases you.
I think it's something like:

void ASDF
{
if (HasItem)== Hammer)
{
SetEntityActive("wooden", true);
}
else
{
SetEntityActive("servant_2", true);
}
}

it says "expected expression value"
If I knew this my map should be fixed.