Girls I need help>> I am too afraid to talk a girl

Girls I really need good advice and please help.

I like a girl. And she work in my office but not under same divisions.
I seen her for the first in canteen and she looked me and I looked her. I am pretty sure that she was just amazed by my looks (I am not saying I am very handsome, But I am not bad looking and I can compete her by looks and I am not bluffing on this) We just gazed each other and she finally drove her eyes away as I never set back my eyes when I look into someones Eyes.

Then their were several instances of our eye contact but I never dared to go and talk her.
There were few instances she use to come to canteen when I was their, and I guess she came in so that I can go and talk her.(form her desk Canteen is fairly visible and I use to watch for her whenever I go to canteen)

Some how I come to know her name and after six hours of collecting my dare, I finally pinged her via a IM in our office. I told her that I like her and want to go for a coffee with her if she is comfortable with this.

She replied that she will let me know .

Ok I waited for few days (2 day) and pinged her back so to know what is her answer. She did not replied.
I again pinged her after waiting for 4 hrs that if I am annoying her she can tell me and i will never get back to her. She told she is busy and will get back to me one free.

I waited for another 2 days and then pinged her back what is her answer. She said she is busy and she is not comfortable with coffee,. I said OK but can we have a chat, she agains said she is not comfortable.

And then I did the most horrible mistake of my life, I ended the talk this way:
__________________________________________________ _
what can I say ?
I am sorry , i have asked too much.(being a stranger)

can we have a chat once, if its OK for you. think freely, be comfortable and give answer.
That is my last word(as no reply means No)
And believe me, I am absolutely cool and no freaking drama running inside.
Your views are equally good as we all have our own beliefs which are best suited for our best.
__________________________________________________ __

And she never replied.

I again pinged her few days later but she never replies me back.

After this I finally decided (Which I have decided too many time before than this one) that today I am going to talk her any how.
I Extended my shift went next to her and passed by but did not dared to talk her.
she gazed me then. I also gazed her.
Then I was little away, and looked at her she also looked me back. BUT hell to me I don't have dare to talk her.
Its not that I do not know how to talk with girls , but I am to pussy for talking this girl.

What should I do ??
I need serious advice do she likes me ?? (based on above descriptions)
What do I do to go an talk in such situation ?

Please help me out.

and she know me that the person who pinged is me, as our photos are visible in our IM:

ME>>>
Do you know me ?
I mean do you know me at least by my face

SHE>>>
i guess i have seen u twice in pantry
tell me

ME>>>
Before I say something, you are not manager right ?
Their is nothing big deal I have to say.
I thought I must talk to you as I like you, I mean just like not much than that not less than that.
Are you comfortable with this.
I know the questions is difficult to answer, but its much difficult to ask someone

SHE>>>
I am not a manager u can go ahead

Please, can someone help me out ???

NO more need help, I got the reply.
She called her boyfriend to talk with me.
And I am sad.