I like my a girl in office my colleague but can't dare to tell her I like you,please advise?

the girl seems to be waiting for me to take 1st step and tell her how i feel about her , the other day she had told my colleague that I don't like chatting whoever wants to tell me something should tell in my face and that guy is someone who is working in same room with me , I had sent her a chat request but she denied she didn't like it , so does it mean she conveyed her message through that guy to me ? the other day this girl was talking with other girl (colleague of mine) about calling something i made a joke that she didnt call u because your mobile might be busy , she then with a surprising accent told me have you ever called me that my number was busy ? In fact i dont have her number . i told her i donve ur number , she said you can have it no problem, i again made a joke that i will miss call u , i will not call u , the call should be made by you she said no i will answer with SMS. so again here is a point she wants me to have her number and she will send sms.