What should i do?

He asked me to be his girlfriend just now!
I don't know what to answer him..
He told me that he has a crush on me for 5months now!
but,i don't know how to react..
Happy?Excited?Sad?Disgusted?

For me,he is just a friend..
Not more than that!
He said he likes me because i'm funny,awlays make him happy,etc..
But,for me,he is just a friend!
How should i react?

Ohhh,i never come across this situation before..
I'm so blur about love and boys..
I don't understand anything about them..
I only read them in books and not reality!
What should i do?

but,i like it every time he calls me..
every time he messages me..
I would get so excited and would smile..
But,what should i do?

For me,
boys are just friends(for now)..
Study first and boys later..
But,he wants the answer!
I don't know what to say..
Either yes or no?

If I said yes,
I'm afraid to get hurt..
If i said no,
I'm afraid this would break our friendship..
What should i do?

What is love?
What are the symptoms for falling in love?
I want to love but i'm afraid to get hurt!